Introduction to Computers

ECE & EEE | I YEAR | II SEMESTER B1360 | COMPUTER PROGRAMMING | UNIT 1
1 |Prepared By : Mr. PRABU.U/AP |Dept. of Computer Science and Engineering | SKCET |
UNIT I
History of Computers – Block diagram of a Computer – Components of a Computer
system –Classification of computers - Hardware – Software – Categories of Software –
Operating System – Applications of Computers – Network structure – Internet and its
services – Intranet – Study of word processor – Preparation of worksheets.
What is Computer?
A computer is an electronic device that manipulates information, or data. It has
the ability to store, retrieve, and process data.
(or)
A computer is a general purpose device that can be programmed to carry out a
set of arithmetic or logical operations automatically.
(or)
A computer is an electronic device that performs diverse operations with the
help of instructions to process the information in order to achieve desired results.
Father of Computer: Charles Babbage (26 December 1791 - 18 October 1871)
Father of Modern Computer: Alan Turing (23 June 1912 - 7 June 1954)
The various characteristics of computers are as follows
1. Speed: Speed is the most important characteristics of computer. Computer having
more speed to perform jobs instantaneously.
2. Accuracy: The computers are perfect, accurate and precise. Accuracy signifies the
reliability of the hardware components of computers.
3. Automatic: A computer works automatically, once programs are stored and data
are given to it,
4. Constant supervision is not required.
5. Endurance: A computer works continuously and will not get tired and will not
suffer from lack of concentration.
6. Versatility: A computer can be put to work in various fields.
7. Reduction of cost: Though initial investment may be high, computer substantially
reduces the cost of transaction.
What is Computer Programming?
Computer programming is the craft of writing useful, maintainable, and
extensible source code which can be interpreted or compiled by a computing system to
perform a meaningful task.
(or)

Computer programming is the process of developing and implementing
various sets of instructions to enable a computer to do a certain task. These instructions
are considered computer programs and help the computer to operate smoothly.
(or)
Computer programming (often shortened to programming, sometimes
called coding) is a process that leads from an original formulation of
a computing problem to executable computer programs.
First Programming Language: FORmula TRANslating System (FORTRAN, Mid 1950s)
First Computer Programmer: Augusta Ada Byron (10 December 1815 - 27 November
1852)
1.1 HISTORY/GENERATION OF COMPUTER
1. First Generation (1942 - 1955)
 In this generation, John Von Neumann introduced the stored program concept.
His idea was to store machine instruction in the memory of the computer along
with data.
 These computers are very huge in size, since they are made of vacuum tubes.
 The first electronic computer was (ENIAC) – Electronic Numerical Integrator and
Calculator using hinge-speed vacuum tubes and switching devices.
 The later version are (EDSAC) – Electronic Delay Storage Automatic Calculator)
using memory delay lines for storage thus increasing the speed and efficiency.
Characteristics
i) Based on: Vacuum Tube Technology
ii) Size: Very large, and required a lot of space for installation
iii) Equipments: Non-portable and very slow
iv) Lack: Versatility and speed
2. Second Generation (1956 - 1965)
 In this generation, the transistors were introduced, so size was greatly reduced
and the speed of the computing was increased.
 The memory capacity was increased and this led to the development of high-
level languages like FORTRAN, COBAL, ALGOL and SNOBOL.
 The floating point arithmetic hardware was widely used. Input and output
processor was included to control input and output operations.
 It relieved CPU from many time consuming routine task. The other advances in
this generation were magnetic tapes, disk storage, operating systems and batch
processing.
Characteristics
i) Based on: Transistor Technology
ii) Size: Smaller as compared to the first generation computers
iii) Computational Time: Reduced to microseconds from milliseconds
iv) Equipments: More portable and generated less amount of heat
v) Language: Assembly Language was used to program computers

3. Third Generation (1966 - 1975)
 In this generation, IC (Integrated Circuit) was used, so size was very much
reduced and the speed of the computer was greatly increased and main memory
also increased.
 In the beginning this generation computers used magnetic core memory, but
later on semiconductor memory is used. Magnetic disks and tapes were used a
secondary memories.
 Cache memory was also used in this generation computers. Microprogramming,
parallel processing, multiprocessing, multi programming and timesharing were
introduced.
Characteristics
i) Based on: IC (Integrated Circuit) Technology
ii) Size: Smaller as compared to previous computers.
iii) Computational Time: Easily portable and more reliable than the second generation
iv) Equipments: Consumed less power and generated less heat.
4. Fourth Generation (1975- 1985)
 In this generation, LSI (Large Scale Integration) and VLSI (Very Large Scale
Integration) IC’s have been used.
 The entire (Central Processing Unit) has been made with a single chip known as
microprocessor.
 Computers were built around the microprocessors; there are 8 bits, 16 bits &
32 bits microprocessors available in the markets.
Characteristics
i) Based on: Microprocessor
ii) Size: Very Small
iii) Equipments: Portable and quite reliable.
5. Fifth Generation (1985 - At Present)
 In fifth generation focuses mainly on two concepts namely Artificial Intelligence
and Expert System.
 The term “Artificial Intelligence” represents any computers system that performs
tasks that embody elements of human intelligence. The areas of AI is used
1. Expert System
2. Robotics
3. Speech Recognition
 An Expert System is a software package that attempts to encode the knowledge
and decision making mechanisms of human specialists. The areas of expert
system are
1. Medical Diagnostics
2. Financial Planning

Sl.
No
Year Switching
Devices Used
Storage Devices Operating
Speed
Software
Used
Applications
1 1942 – 55 Vacuum Tubes Punched with
magnetic drum
memory
Milliseconds Machine
language
Simple
Applications
2 1956 – 65 Transistors Magnetic core, tapes
and disks
Micro seconds Assembly
language
Business,
Scientific,
research
3 1966 – 75 Integrated
Circuits
Magnetic disks Nanoseconds High level
languages –
Fortran, Basic,
Cobol, Pascal,
Prolog, C and
C++
4 1975 – 85 LSI and VLSI Semiconductor
memory
1 to 10 nano
seconds
Third
generation
languages and
Dbase, Foxpro,
Oracle, SQL,
etc.,
Engineering
Design,
Scientific
research,
business
online systems
5 1986 – at
present
VLSI Floppy Disk,
Compact Disk, and
Hard Disk
1 to 100 nano
seconds
3GL & 4Gl,
Lisp, AI logic
etc.,
Speech
Recognition,
Expert system
and Robotics
1.2 BLOCK DIAGRAM OF COMPUTER
The architecture of the computer has not changed since decades, but the
technology used to accomplish those operations may vary from once computer to
another computer. However, the basic computer organization remains the same for all
computer systems.
Figure: Block Diagram of Computer
Central Processing Unit
Memory Unit
Input Unit
Control Unit Arithmetic/
Logic unit
Output Unit
Data Flow
Control Flow / Instruction Flow

The block diagram of the computer system have the following three units, each
functional unit corresponds to their basic operations performed.
1. Input Unit
2. Central Processing Unit
3. Output Unit
1. Input Unit
 Computers must need the data and instructions in order to solve any problems.
Therefore, we need to put the data and instruction into the computer.
 The input unit is used to send information or instructions or commands to the
computer.
 The data received from the input unit is immediately stored in main memory and
then processed.
 The input unit consists of one or more input devices. There are number of
devices that perform the functions of input devices.
 Input may be pressing a key in a keyboard or moving of mouse or movement of a
joystick etc.
i) Functions
 Accept data instructions from the outside world
 Convert it to a form that the computer can understood
 Supply the converted data to the computer system for further processing
ii) Input Devices
1. Keyboard
2. Mouse
3. Light Pen
4. Digitizer
5. Track ball
6. Joystick
2. Central Processing Unit (CPU)
 It is the heart of the computer system. ie., all operations are carried out in CPU
only.
 In most modern computers, a single IC does the job of following operations.
 It performs all calculations and all decisions
 It controls and co-ordinates all units of the computer
 It interprets instructions of a program
 It stores data temporarily and monitors external requests
The CPU is sub-divided into the following sub-systems
i) Control Unit
ii) Arithmetic and Logical Unit
iii) Memory Unit
a) Primary storage
b) Secondary storage

i) Control Unit
 The control unit instructs the computer how to carry out program instructions. It
directs the flow of data between Memory and Arithmetic Logical Unit.
 It controls and co-ordinates the entire computer system. The control unit
controls all other units in the computer.
 The input unit does not know when to receive data and where to put the data in
the storage unit after receiving it.
 The control unit gives the necessary instructions to the input unit. Similarly, the
control unit also controls that should be sent to the output unit.
ii) Arithmetic and Logical Unit
The arithmetic/logic unit (ALU) contains the electronic circuitry that executes all
arithmetic and logical operations on the data made available to it.
Arithmetic Unit
 The arithmetic unit contains the circuitry that is responsible for performing the
actual computing and carrying out the arithmetic calculations, such as addition,
subtraction, multiplication, and division.
 It can perform these operations at a very high speed.
Logic Unit
 The logic unit enables the CPU to perform logical operations based on the
instructions provided to it. These operations are logical comparison between
data items.
 The unit can compare numbers, letters, or special characters and can then take
action based on the result of the comparison.
 Logical operations of Logic unit can test for three conditions: equal-to condition,
less-than condition, and greater-than condition.
iii) Memory Unit
 Memory is the part of computer which holds data for processing and other
information. It is also called as Main Memory or Primary Memory.
 The information given from the input unit is immediately stored in Main
Memory.
 It is a temporary storage (volatile) ie., whenever the power lost, the stored
information in Main Memory will be erased, to avoid this situation, we can store
immediately in Secondary Memory
Primary storage:
 The primary storage is also called as “main memory”, stores and access
information very fast.
 This is generally used to hold the program being currently executed in the
computer, the data being received from the input unit, the intermediated and
final results of the program.
 The primary memory contents generally loses its contents when we switch off
the computer
 Primary storage is also known as system memory, internal, temporary and
“RAM”
 Installed on the main computer board (Motherboard)
 Typically comprised of IC’s (Integrated Circuits)
 Fast access –usually in the order of nano seconds

Secondary storage:
 The secondary storage is also known as Auxiliary storage. It is used like an
archive. It may store several programs, documents, databases etc.
 The program that we want to run on the computer is first transferred to the
primary memory before it can run. Similarly, after running the program, if we
need to save the results, we will transfer them to the secondary storage.
 The Secondary memory is slower and cheaper than the primary memory. Some
of the commonly used secondary memory devices are Floppy diskette, Zip
diskette, Hard disk and Magnetic disks and tapes etc.,
 It is the permanent storage, the data or information stored in the storage will not
be erased when the power is lost. It is also called as non-volatile memory.
 Secondary memory is also known as disk storage, external storage.
3. Output Unit
 Devices used to get the response or result of a process from the computer is
called output. Output unit is the communication between the user and the
computer.
 The output unit of a computer provides the information and results of a
computation to the outside world. As we know, computers do not work in the
decimal system, they work in the binary system.
 Therefore if required, the output unit also converts the binary data into a form
that user can understand.
 Printer and Visual Display Unit (VDU: also called Monitor/screen) are
commonly used output devices
1.3 COMPONENTS OF A COMPUTER
Components of a computer system can be divided into following two main groups
 Hardware
 Software
Hardware
Computer hardware is the collection of physical parts of a computer system. The
hardware devices attached to the computer are called peripheral devices, which include
all input, output and secondary storage devices.
1. Mother board 8. CD-ROM drive
2. Processor 9. Keyboard
3. Memory (RAM) 10. Mouse
4. Case (Chassis) 11. Monitor
5. Power supply 12. Video Card
6. Hard Disk Drive 13. Speakers
7. Floppy Disk Drive
1. Motherboard
 It is the core of the computer system. Everything is connected to it and it controls
everything in the system.
 It contains Processor, Connectors ports, (PCI)Peripheral Component
Interconnect, Northbridge, Southbridge, CPU Socket, IDE Connector, CMOS
Battery, Fan, RAM Slots, Power connector.

2. Processor
 It is the engine of the computer It is known as central processing unit(CPU).
 The processor reads the program instructions from the memory.
 These instructions tell the processor what it has to do to complete the work that
the user wants.
 The processor then executes them. Speed is counted in Mega Hertz (MHZ), which
means million of cycles per second.
3. Memory
Random Access Memory(RAM)
 This is the main memory that holds all the programs and data used by the
processor. If you switch-off the computer, everything in the RAM is cleared.
Read Only Memory(ROM)
 ROM cannot be erased. It contains instructions to get the system to load an
operating system and other programs from one of the disk drives into the main
memory.
4. Case (Chassis)
 The case is the outer shell or box that houses most of the computer components.
5. Power Supply
 Power supply feeds electrical power to every single part in the PC.
 It converts 110 volts a/c supply voltage into 3.3 volts, 5 volts and 13 volts power
that the system requires for the operation.
6. Hard Disk Drive
 It consists of spinning platters of aluminium or ceramic coated with a magnetic
media. It contains all programs, data and information.
 The platters are available in various sizes. Hard Drivers can be made with
different storage capacities based on the density, size, and number of platters.
7. Floppy Disk Drive
 PCs manufactured in the last 10 years use a standard 3.5 inch, 1.44 MB capacity
floppy drive.
 Floppy drive has two read/write heads, one for each side of the disk.
8. CD-ROM Drive
 It stands for Compact Disk – read Only Memory. One that holds music, data,
information. Data can be entered into CD using CD Writer.
9. Keyboard
 It is the main input devices, used to input text or enter commands into the PC.
 There are some special keys like Esc (Escape), Ctrl (Control), and Alt (Alternate).
 There are also some keys across the top of the keyboard labelled F1, F2, F3, and
so forth. Those are called the function keys
10. Mouse
 The computer mouse is considered an input device. With a click of a button, the
mouse sends information to the computer.

 A typical mouse has two buttons. At the top of the device you will find a left and
right button which allows for “clicks”.
 There is a scrolling wheel between the two buttons.
11. Monitor
 Monitor of a computer is a high-resolution screen similar to a high-quality
television. The monitor screen is made up of red, green, and blue dots.
 Monitors are used to display what is going on in our computer. They can run at
various resolutions and refresh rates.
12.Video card
 It sends the contents of its video memory to your monitor at the rate of 60
times/second.
13. Speakers
 The computer can also produce voice output (Audio data). Speaker servers as a
voice output device. User can also hear music/songs using voice output system.
1.4 CLASSIFICATION OF COMPUTERS
1. Based on principle of working
Based on the principles of operation, computers are classified into three types
namely analog computers, digital computers and hybrid computers.
i) Analog Computers
 A number is represented in the machine by a physical quantity as measured by
some system of units.
 The physical quantity can be anything electric voltage, electric current, pressure,
temperature, speed.
Computer classification based on
Principle of working Processing mode Size, cost, and
performance
Analog
Digital
Hybrid
Batch
Real Time
Time sharing
Micro
Mini
Mainframe
Super

 It is in the form of sine waves. Analog signal is a continuous variable
electromagnetic wave and it consume an infinite number of voltage or current
values.
ii) Digital Computers
 It operate on digital data such as numbers. It uses binary number system in
which there are only two digits 0 and 1.
 Digital computers are much faster than analog computers and are more accurate.
Digital computers are largely used for business and scientific applications.
iv) Hybrid Computers
 It is a combination of both digital and analog computers. Analog-to-digital and
digital-to-analog converters are used for transforming the data.
 These used in hospital to monitor the patients temperature.
 These measurements which in analog and then converted into numbers and
supplied to digital components in the system.
2. Based on Processing Mode
i) Batch Processing
A number of jobs are entered into the computer, stored internally and then
processed sequentially.
ii) Real Time
Immediate response, for example in industrial process control system, real-time
computers have to collect data about the production process and use it to control
machines in the factory.
iii) Time Sharing
Time Sharing allows many different users to use a single computer
simultaneously.
3. Based on Size, Performance, Cost
Computers are available in many types and sizes. Some computers can fit in the
palm of your hand. Some can occupy an entire room. Based on the size, performance,
and cost computers are generally classified as Micro, Mini, Mainframe and Super
computers.
i) Micro Computer
 A micro computer is a small, low cost digital computer, which usually consists of
a microprocessor, a storage unit, an input channel, and an output channel, all of
which may be on one chip inserted into one or several PC boards.
 The addition of a power supply and connecting cables, appropriate peripherals
(keyboard, monitor, printer, disk drives, and others), an operating system and
other software programs can provide a complete micro computer system.
 IBM-PC, Pentium 100, IBM-PC Pentium 200 and Apple Macintosh are some of the
examples of micro computers.
 Micro computers include desktop, laptop, and hand-held models such as PDAs
(Personal Digital Assistants).

a)Desktop Computer
 Desktop computer, also known as Personal Computer (PC), is principally
intended for standalone use by an individual. These are the most common type
of micro computers.
 These micro computers typically consist of a system unit, a display monitor, a
keyboard, internal hard disk storage, and other peripheral devices.
 Some of the major personal computer manufacturers are APPLE, IBM, Dell and
Hewlett-Packard.
b) Laptop
 A laptop is a portable computer, that is, a user can carry it around. Since the
laptop computer resembles a notebook, it is also known as "notebook".
 Laptops are small computers enclosing all the basic features of a normal desktop
computer.
 The biggest advantage of this computer is that one can use this computer
anywhere and at anytime, especially when one is travelling.
c) Hand-held Computers
 A hand-held, also called Personal Digital Assistant (PDA), is a computer that can
conveniently be stored in a pocket (of sufficient size) and used while the user is
holding it.
 PDAs are essentially small portable computers and are slightly bigger than the
common calculators.
 A PDA user generally uses a pen or electronic stylus, instead of a keyboard for
input. Since these computers can be easily fitted on the palm, they are also
known as palmtop computers.
 Some examples of PDAs are Apple Newton, Casio Cassiopeia and Franklin
eBookMan.
ii) Mini Computers
 The mini computer is a small digital computer whose process and storage
capacity is lesser than that of a mainframe, but more than that of micro
computer.
 Its speed of processing data is in between that of a mainframe and a micro
computer.
 It is about the size of a two drawer filing cabinet.
 It is capable of supporting from 4 to about 200 simultaneous users.
 It serves as a centralized storehouse for a cluster of workstations or as a network
stations in server.
iii) Mainframe Computer
 A mainframe is an ultra-high performance computer made for high-volume,
processor-intensive computing.
 It capable of processing data at very high speeds, hundreds of million
instructions per second.
 It is able to process and store more data than a mini computer and far more than
a micro computer.
 It is designed to perform at a faster rate than a mini computer and at even more
faster rate than a micro computer.

 Examples of mainframe computers are IBM's ESOOO, VAX 8000 and CDC 6600.
iv) Super Computer
 Super computers are the special purpose machines, which are specially designed
to maximize the numbers of FLOP (Floating Point Operation per Second).
 A super computer has the highest processing speed at a given time for solving
scientific and engineering problems.
 It contains a number of CPUs that operate in parallel to make it faster.
 Its processing speed lies in the range of 400-10,000 MFLOPS (Millions of Floating
Point Operation per Second).
 CRAY-3, Cyber 205 and PARAM are some well known super computers.
1.5 HARDWARE
Hardware refers to all visible devices that are assembled together to build a
computer system these include various input devices, central processing unit, output
devices, and memory.
Central Processing Unit
Registers
Input Unit
Control Unit Arithmetic
/Logic unit
Output Unit
Memory Unit

1. Central Processing Unit
 The central processing unit (CPU) referred to as the "brain" of a computer
system, converts data (input) into meaningful information (output).
 It is a highly complex, extensive set of electronic circuitry, which executes stored
program instructions.
 A CPD controls all internal and external devices, performs arithmetic and logic
operations, and operates only on binary data, that is, data composed of 1’s and 0’s.
 It also controls the usage of main memory to store data and instructions, and
controls the sequence of operations.
 The central processing unit consists of three main subsystems, the
Arithmetic/Logic Unit the Control Unit and the Registers.
2. Arithmetic/Logic Unit (ALU) :
 The arithmetic/logic unit (ALU) contains the electronic circuitry that executes all
arithmetic and logical operations on the data made available to it.
 The data required to perform the arithmetic and logical functions are inputs
from the designated registers.
ALU comprises of two units: Arithmetic Unit and Logic Unit.
i) Arithmetic Unit:
The arithmetic unit contains the circuitry that is responsible for performing the
actual computing and carrying out the arithmetic calculations, such as addition,
subtraction, multiplication, and division. It can perform these operations at a very high
speed.
ii) Logic Unit:
 The logic unit enables the CPU to perform logical operations based on the
instructions provided to it. These operations are logical comparison between
data items.
 The unit can compare numbers, letters, or special characters and can then take
action based on the result of the comparison.
 Logical operations of Logic unit can test for three conditions: equal-to condition,
less-than condition, and greater-than condition.
3. Control Unit
 This unit checks the correctness of sequence of operations.
 It fetches program instruction from the primary storage unit, interprets them,
and ensures correct execution of the program.
 It also controls the input/output devices and directs the overall functioning of
the other units of the computer.
4. Output Unit
 Output devices take the machine-coded output results from the CPU and convert
them into a form that is easily readable by human.
 Output unit processes data into useful information.
 The outputs, which can be easily understood and used by human beings, are in
the form of hard copy and soft copy.
 The physical form of output is known as hard copy. The electronic version of an
output, which usually resides in computer memory is known as soft copy:
 Some of the commonly used output devices are monitors, printers, plotters, and
audio response.

5. Memory
 Computers require memory to process data and store output.
 Memory refers to the electronic holding place for instructions and data.
 Some data will be required instantaneously, while others may not be needed for
extended periods.
 Likewise, CPU requires memory to handle the intermediate results and to store
the final output. Hence, we can classify memory into two broad categories:
primary memory (to handle the data) and secondary memory (to store the
output).
i) Primary Memory: Primary memory, also known as main memory, stores data and
instructions for processing. Primary memory can be further classified into random
access memory (RAM) and read only memory (ROM).
ii) Secondary Memory Secondary memory, also known as auxiliary memory or external
memory is used for storing instructions (software programs) and data, since main
memory temporary and limited in size. This memory is least expensive and has much
larger storage capacity than primary memory.
1.6 SOFTWARE
It is basically “the set of instructions grouped into programs that make the
computer to function in the desired way. It is a collection of programs to perform a
particular task”.
S.NO HARDWARE SOFTWARE
1
Used to store and execute various
software
Set of instruction to interact with
computer to perform a specific task
2
Monitors, CPU, keyboard, mouse, CD
Drive, Pen drive, Printers, Scanners,
Modem
Microsoft word, Excel, Windows XP, ..
3
Once installed not to change day by
day
New versions are released
4 It is physical in nature It is logical in nature
1.7 CATEGORIES OF SOFTWARE
1. System Software
 It consists of programs that work with users directly. Performs computer
related tasks, such as managing input and output devices.
 Some examples of system software are operating system, device drivers,
language translators, and system utilities.
i) Operating System
 OS is the first layer of software loaded into computer memory when it starts up.
 As the first software layer, all other software that gets loaded after it depends on
it for various common core services.
 These common core services include disk access, memory management, task
scheduling, and user interfacing.

 The OS organizes and controls the hardware. Examples of operating system are
windows XP, Unix, Linux, Windows 7.
ii) Device Drivers
 Device drivers are system programs that are responsible for proper functioning
of devices.
 Every device whether it is a printer, monitor, mouse, keyboard, has a driver
program associated with it for its proper functioning.
 Whenever a new device is added to the computer system, new device drive must
be installed before the device is used.
iii) Language Translators
 Computers only understand a language consisting of ‘0’s and ‘1’s called machine
language.
 To ease the burden of programming entirely in ‘0’s and ‘1’s, special programming
language called high-level programming language.
 With every programming language, a language translator was also developed,
which accepts the programs written in a programming language and executes
them by transforming them into a form suitable for execution.
 Assembler : the Assembly language program must be translated into machine
code by a program called Assembler. It is a translator program used to translate
an Assembly Language program into a Machine Language program.
 Compiler : It is a translator system program used to translate a high-level
language program into a machine language program. The compiler translates
source code (i.e., user written program) into object code (binary form).
 Interpreter : it is used to translate a high-level language program into a
machine language program. It translates and also executes the source code line-
by-line.
iv) System utility
 System utility programs perform day-today tasks related to the maintenance of
the computer system.
 They are generally small programs, having specific tasks to perform.
 Some utility programs are usually provided along with the operating system,
some free while some need to be purchased from the third party.
2. Application Software
 Application Software is the set of programs necessary to carry out operations for
a specific application.
 It may also be a collection of programs termed as Software Package, which is
used for database management etc.
 Application software includes following
i) Word Processors
 A Word Processor is a program that enables you to perform word processing
functions.
 To perform word processing, word processing software and a printer is needed.

 Commonly used word processors are Microsoft Word, Word Perfect etc.
ii) Spreadsheets
 A Spreadsheet is a table of values arranged in rows and columns. Each value can
have a predefined relationship to the other values.
 If you change one value, you may need to change other values as well.
 Example: Processing pay roll and other financial records.
 Commonly used spreadsheets are Microsoft Excel, Lotus 123 etc.
iii) Database Management Systems (DBMS)
 A DBMS is a collection of programs that enable you to store, modify and extract
information from a database.
 Examples: Computerized library systems, Automated Teller Machines (ATM) etc.
 Commonly used DBMS are Oracle, MS SQL Server, MS Access etc.
iv) Presentation Software
 It includes functions for creating charts and graphs and for inserting text to
present one's work orally in the presence of audience.
 Presentation software allows the user to create presentations by producing
slides.
 Commonly used presentations softwares are Microsoft PowerPoint, Havard
Presentation Graphics etc.
v) Desk Top Publishing (DTP) Software
 It is used for preparing books, magazines, newsletters etc. The term DTP is used
to describe the creation of printed documents using a desktop computer.
 Commonly used DTP softwares are Adobe PageMaker, Quark Express etc.
vi) Image Processor
 Image Processor enables you to create, edit, manipulate, add special effects, view,
print and save images.
 Using this, you can darken or lighten an image, rotate it, adjust its contrast etc.
 Commonly used image editing softwares are CorelDraw, Adobe Photoshop,
Adobe Illustrator etc
1.8 OPERATING SYSTEM
 An operating system is a program that manages the computer hardware.
 It also provides a basis for application programs and act as an intermediary
between a user of a computer and the computer hardware.
 It controls and coordinates the use of the hardware among the various
application programs for the various users.
1. Types of Operating Systems
i) Mainframe Operating System
 The operating systems for mainframes are oriented towards processing many
jobs at a time, most of which need huge amounts of I/O.
 They offer three kinds of services: Batch, Transaction Processing and Time
Sharing.
 Batch processing system allows only one program to run at a time. It works on a
series of programs that are held in a queue. Its function is to schedule the jobs
according to priority and resources required.
 Transaction processing systems handle large numbers of small requests.
Example: Cheque processing at a bank.

 Time sharing systems allows multiple remote users to run jobs on the computer
at a time, such as querying a big database.
ii) Server Operating System
 It runs on servers, which are either very large Personnel Computer, Workstation
or even Mainframe.
 It serves multiple users at a time over a network and allow the users to share
hardware and software resources.
 Servers can provide print service, file service or web service. Typical Server
Operating Systems are UNIX and Windows 2000.
iii) Multiprocessor Operating System
 An increasingly common way to get major-league computing power is to connect
multiple CPUs into a single system.
 Depending on how they are connected and what is shared, these systems are
called Parallel Computers, Multi-computers or Multi-processors. They need
special operating systems.
 But, often there are variations on the server operating systems with special
features for communication and connectivity.
iv) Personnel Computer Operating System
 Its function is to provide a good interface to a single user. It is widely used for
word processing, Spreadsheets and Internet access.
Example: Windows 98, Windows 2000, Linux and Macintosh Operating System
v) Real-time Operating system
 This system is characterized by having time as a key parameter. For example, in
industrial process control system, real-time computers have to collect data about
the production process and use it to control machines in the factory. Often, there
are hard deadlines that must be met with.
 For example, if a car is moving down an assembly line, certain actions must be
take place at certain instants of time.
 If a welding robot welds too early or too late, the car will be ruined. If the action
absolutely must occur at a certain moment, we have a hard real-time system.
 In soft real-time system, missing an occasional deadline acceptable.
vi) Embedded Operating System
 Embedded systems run on the computers that control devices that are not
generally thought of as computers, such as TV sets, Microwave ovens and Mobile
telephones.
 These have some characteristics of real-time systems, but also have size, memory
and power restrictions.
 Examples: Windows CE (Consumer Electronics) and PalmOS.
vii) Smart Card Operating System
 It runs on smart cards, which are credit card-sized devices containing a CPU chip.
It has severe processing power and memory constraints.
 Some of this systems can handle only a single function such as electronic
payments. But others can handle multiple functions on the same smart card.

2. Functions of Operating System
i) Process Management
 A key concept in all operating systems is the Process. A process is basically a
program in some stage of execution.
 As a process manager, the operating system handles the creation and
termination of processes, suspension and resumption of processes and
scheduling and synchronization of processes.
Deadlocks: A process is said to be deadlocked, if it is waiting for an event which will
never occur. There are four conditions to be present for a deadlock to occur. These
conditions are: Mutual exclusion, Hold and wait, No pre-emption and Circular wait. If
one of the conditions is absent, no deadlock is possible.
System calls: The interface between the operating system and the user program is
defined by the set of System calls that the operating system provides.
Kernel: Kernel is part of an operating system that implements the interaction with
hardware and the sharing of resources.
ii) Memory Management
 Every computer has some main memory that it uses to hold executing programs.
In a simple operating system, only one program at a time is in memory.
 To run a second program, the first one has to be removed and the second one
placed in memory.
 The part of the operating system that handles the management of main memory
is called the Memory Manager.
iii) File Management
 The operating system is responsible for File Management. File management
means creation, deletion, reading and writing of files. Before a file can be read, it
must be located on the disk and opened.
 After it has been read, it should be closed. To provide a place to keep files, the
operating system has Directory as a way of grouping files together.
iv) Device Management
 Every operating system has an I/O subsystem for managing its I/O Devices. It
detects device failures and notifies the same to the user.
 The device manager manages the hardware resources. It provides an interface to
hardware for application programs.
v) Security Management
 Computers contain large amounts of information that users often want to keep
confidential. This information may include electronic mail, business plans, tax
returns and much more.
 It is upto the operating system to manage the system security so that files, for
example, are accessible each one a 9 bit binary protection code.
 In addition to file protection, the operating system protects the file system from
unwanted intruders, both human and non-human (eg., viruses)

vi) User Interface
 A User Interface is a set of commands or menus through which a user
communicates with the system hardware. The user interface is the layer that
actually interacts with the computer operator.
 Operating system organizes applications so that users can easily access them, use
them and store application data.
1.9 APPLICATIONS OF COMPUTERS
In the last few decades, computer technology has revolutionized the businesses
and other aspects of human life all over the world. Some of the areas where computers
are being used are listed below:
1.Science
 Scientists have been using computers to develop theories, to analyze, and test the
data. The fast speed and accuracy of the computer allow different scientific
analyses to be carried out.
 They can be used to generate detailed studies of how earthquakes affect
buildings or pollution affects weather pattern.
 Satellite-based applications could not have been possible without the use of
computers. It would also not be possible to get the information of our solar
system and the cosmos without computers.
2.Education
 Computers have also revolutionized the whole process of education.
 Currently, the classrooms, libraries, and museums are utilizing computers to
make education much more interesting.
 Unlike recorded television shows, Computer Aided Education (CAE) and
Computer Based Training (CBT) packages are making learning much more
interactive.
3. Medicine and Health Care
 There has been an increasing use of computers in the field of medicine.
 Now doctors are using computers right from diagnosing the illness to monitoring
a patient's status during a complex surgery.
 By using automated imaging techniques, doctors are able to look inside a
person's body and can study each organ in detail (such as CAT scans or MRI
scans), which was not possible a few years ago.
4. Engineering Architecture/Manufacturing
 The architects and engineers are extensively using computers in designing and
drawings.
 Computers can create objects that can be viewed from all the three dimensions.
 By using techniques like virtual reality, architects can explore houses that have
been designed but not built.
 The manufacturing factories are using computerized robotic arms in order to
perform hazardous jobs.

5.Entertainment
 Computers are finding greater use in entertainment industry. They are used to
control the images and sounds.
 Special effects, which mesmerize the audience, would not have been possible
without computers.
 In addition, computerized animation and colourful graphics have modernized the
film industry.
6.Communication
 E-mail is one of the communication media in which computer is used.
 Through e-mail, messages and reports are passed from one person to one or
more persons.
 The benefit of e-mail service is that while transferring the messages it saves time,
saves paper, and so on.
 Moreover, the person who is receiving the messages can read the messages
whenever he is free and can save it, reply it, forward it or delete it from the
computer.
7. Publishing
 Computers have created a field known as DTP (Desktop Publishing).
 In DTP with the help of a computer and a laser printer one can perform the
publishing job all but oneself.
8.Banking
 In the field of banking and finance, computers are extensively used.
 People can use the ATM (Automated Teller Machine) services 24 hours of the day
in order to deposit and withdraw cash.
 When the different branches of the bank are connected through computer
networks, then the inter branch transactions such as cherub and draft can be
done by the computers without any delay.
1.10 NETWORK STRUCTURE
 Network is a group of computers connected together.
 Group of two or more system linked together.
 Communication is about the transfer of information from a sender, across a
distance, to a receiver. Communication is an act of transmitting messages.
 We transmit information or data by using two types of signals, namely analog
and digital. Computers communicate with digital signals.
 The older forms of communications technology, such as telephones and radios,
use analog signals.
Types of Networks
1. LAN (Local Area Network)
2. MAN (Metropolitan Area Network)
3. WAN (Wide Area Network)

1. Local Area Network (LAN)
 Smallest network compared to the other two networks.
 The simplest form of LAN is to connect two computers together.
 LAN is operated within a limited physical area, such as at home, school, a single
building or several buildings.
 LAN works at the speed of 100 or 1000 Mbps.
Figure: Local Area Network
2. Metropolitan Area Network (MAN)
 Companies that have several branches within the Mumbai city such as banks, use
a MAN. Can be a collection of several LANs within the same city.
 MAN can be defined as a group of computers and network devices connected
together within a large physical area.
 A MAN is typically owned and operated by a single entity such as a government
body or large corporation.
Figure: Metropolitan Area Network
3. Wide Area Network (WAN)
 The largest network of all network types. Internet is the largest WAN in the
world. WAN generally covers large distances such as states, countries or
continents.
 Eg: Local banks have always maintained their business online by connecting all
computers of their branches in the countries.
 International banks also use WAN to connect their computers all over the world.
 WAN is a group of MANs or LANs or the mixture of both networks.

Figure: Wide Area Network
Comparison of LAN, MAN, WAN
CRITERIA LAN MAN WAN
COST Low High Higher
NETWORK SIZE Small Larger Largest
TRANSMISSION
MEDIA TYPE
Twisted-pair
Twisted-pair and
fiber-optic cables
Fiber optic, radio
wave and satellite
NUMBER OF
COMPUTERS
Smallest Large Largest
Network Topology
Network topology is the arrangement of the various elements (links, nodes,
etc.) of a computer network.
1. Ring 2. Bus 3. Star 4. Tree 5. Mesh
1. Ring Topology
 It can be found in LAN.
 Each node directly connect to two neighbouring nodes.
 A server may exist in a ring network, but it will not connect to all the nodes in the
network.
 The server, like other nodes, will only communicate to its two neighbouring
nodes.
 A ring topology consists of all computers and other devices that are connected in
a loop.
Figure: Ring Topology

2. Bus Topology
 Very common in LAN
 Must have a common backbone (the central cable) to connect all devices.
 All nodes share the backbone to communicate with each other on the network.
 Sometimes, a bus network has more than one server.
 Sometimes, a server is not needed on the network.
 A bus topology consists of a single central cable to which all computers and other
devices connect.
Figure: Bus Topology
3. Star Topology
 A star network is found in a Local Area Network setting.
 A star network must have a host which acts as the centre.
 The host can be a server, hub or router.
 In a star network, every node will not connect to the neighbouring nodes.
 Every node must connect to the host in order to communicate.
 A star topology consists of a central host which acts as the centre, and all nodes
connect to the host.
 The host will control the flow of communication in the network.
Figure: Star Topology
4. Tree Topology
 Tree topology is the combination of the bus and the star topology.
 The tree like structure allows you to have many servers on the network and you
can branch out the network on many ways.
 Nodes of some devices are linked to a centrally located hub which is called the
active hub.

Figure: Tree Topology
5. Mesh Topology
 Mesh Network is a network where all the nodes are connected to each other and
is a complete network.
 In a Mesh Network every node is connected to other nodes on the network
through hops.
 It is called the self healing technology where it receives data one way or the
other.
 Data is automatically configured to reach the destination by taking the shortest
route.
 Internet is a mesh network.
Figure: Mesh Topology
1.11 INTERNET AND ITS SERVICES
INTERNET
 A network of networks, joining many government, university and private
computers together and providing an infrastructure for the use of E-mail, file
archives, hypertext documents, databases and other computational resources.
Origin/Motivation of Internet
The motivation behind the creation of the Internet were twofold:
1. Researchers wanted to communicate with each other and share their research
papers and documents.
2. The U.S military system wanted a strong communications infrastructure to
withstand any nuclear attack by the erstwhile Soviet Union.

 By 1970’s, ARPA (Advanced Research Projects Agency) developed a protocol
known as TCP/IP (Transmission Control Protocol/Internet Protocol) for
transferring data between the networks. TCP/IP is the core of Internet.
Applications include
 E-Commerce and E-mail
 EDI (Electronic Data Interchange)
 Information Publishing
 Information retrieval
 Video Conferencing
Internet classification are
i) Academic Internet and ii) Business Internet
Types of Internet Connection
The modem must be connected to a telephone line to access the web. Some of the
common types of Internet access are:
 Dial-up
 ISDN (Integrated Services Digital Network)
 Cable Modem
 Leased Line
 DSL (Digital Subscribed Line) Service
 Broadband
Internet Service Provider (ISP)
 An ISP is an organization that provides individuals and other companies access
to the Internet and other related services such as Web Site building and virtual
hosting.
 There are international service providers, national service providers, regional
service providers, and local service providers.
Web Pages
A webpage is a HTML document that is present in a web server and that has an
URL so that it can be processed via the web
Example: www.pondiuniv.edu is the website name and it consists of several web pages
like home.html, contactus.html etc.
Home Page
A home page is the front door of the web site. When the web user is typing a
website name in the browser, the home page is displayed first.
Web Browsers
A Web Browser is a software tool that computers use to communicate with web
servers on the Internet. Web browsers enable to download and display the web pages
that user requests.
a) Microsoft Internet Explorer (IE)
b) Netscape Navigator
c) Opera
d) Safari
e) Google Chrome

Uniform Resource Locator (URL)
 The uniform resource locator (URL) is a standard for specifying any kind of
information on the Internet.
 The URL defines four things: method, host, port and path
Figure : URL
Domain Name Server (DNS)
DNS is a protocol that can be used in different platforms. In the Internet, the
domain name space (tree) is divided into three different sections
 Generic Domains
 Country Domains
 Inverse Domains
Label Description
com Commercial organizations
edu Educational institutions
gov Government institutions
int International Organizations
mil Military groups
net Network support centers
org Nonprofit Organizations
INTERNET SERVICES
Some of the important services provided by the Internet are briefed in the
following few sections.
World Wide Web (WWW)
 The World Wide Web (abbreviated as the Web or WWW) is one of the most
popular services available on Internet.
 It is a subset of the Internet and it presents text, images, animation, video, sound,
and other multimedia in a single interface.
IM, Chatting
Internet
Telephony
Telnet
Mailing List
FTP
E-Mail
Newsgroups
Commerce
Internet

Electronic Mail (E-mail)
 Electronic mail, or e-mail, is a fast, easy, and inexpensive way to communicate
with other Internet users around the world.
 It is one of the basic and earliest services of the Internet and the most used
application on the Internet too.
File Transfer Protocol (FTP)
 FTP or File Transfer Protocol is a set of rules that enables a user to log on to
another computer and transfer information between it and his/her computer.
 It was the first service developed for the Internet so that government and
educational institution could easily exchange files.
Telnet
 The word "telnet" is derived from telecommunications and network and is a
protocol that allows a user to log on to a remote computer.
 Telnet is also known as remote login, which means connecting one machine to
another in such a way that a person may interact with another machine as if
being used locally.
Internet Relay Chat (IRC)
 IRC or Internet Relay Chat is a service on the Internet that allows the people to
communicate in real-time and carryon conversations via the computer with one
or more people.
 It provides the user with the facility to engage in simultaneous (synchronous)
online "conversations" with other users from anywhere in the world.
Chatting
 Chat programs allow users on the internet to communicate with each other by
typing in real-time.
Instant Messaging
 A variation of chat is instant messaging where a user on the web can contact
another currently logged in and type a conversation.
 To avail this Internet service, the user must have software called instant
messenger installed on the system.
Internet Telephony
 Internet telephony is the use of Internet rather than traditional telephone
company infrastructure, to exchange spoken or other telephonic information.
 There are many Internet telephony applications available. Some, such CoolTalk
and NetMeeting come bundled with popular web browsers.
Commerce through Internet
 Today business is taking place through electronic telecommunication media.
 Nowadays, various organizations offer the facility of shopping online.
 This type of business model is known as Electronic Commerce or E-commerce.
 E-commerce refers to buying and selling goods and online. Some of the well-
known e-commerce sites are www.amazon.com and www.ebay.com.

Newsgroups (Usenet)
 Newsgroups are international discussion groups that focus on a particular topic
and help in gathering information about that topic.
 The topics discussed here cover all the fields such as politics, computers,
technology, and many more.
1.12 Intranet
 Intranet is a private network that allows people to access information within the
organization by using the web browsers and other internet programs with the
help of TCP/IP.
 The intranets are also called as the internal webs, because they allow an
organization to have its own private web sites for use only by users on the
intranet.
Benefits of Intranets
Workforce productivity
 Intranets can also help users to locate and view information faster and use
applications relevant to their roles and responsibilities.
 With the help of a web browser interface, users can access data held in any
database the organization wants to make available, anytime
Time
 With intranets, organizations can make more information available to employees
on a "pull" basis (i.e., employees can link to relevant information at a time which
suits them) rather than being deluged indiscriminately by emails.
Communication
 Intranets can serve as powerful tools for communication within an organization,
vertically and horizontally.
 From a communications standpoint, intranets are useful to communicate
strategic initiatives that have a global reach throughout the organization.
Cost-effective
 Users can view information and data via web-browser rather than maintaining
physical documents such as procedure manuals, internal phone list and
requisition forms.
 This can potentially save the business money on printing, duplicating documents,
and the environment as well as document maintenance overhead.
Promote common corporate culture
 Every user is viewing the same information within the Intranet.
Enhance Collaboration
 With information easily accessible by all authorized users, teamwork is enabled.
Cross-platform Capability
 Standards-compliant web browsers are available for Windows, Mac, and UNIX.

1.13 STUDY OF WORD PROCESSOR
 A word processor is an application whose principal function is the preparation of
documents and letters used in an application called Microsoft Word which forms
part of the Microsoft Office package.
 Word is a WYSIWYG (What you see is what you get) application.
Uses of Word Processing Software
 Word Processing Software is used to Type the text, Save, Format (Both
Paragraph & page Formatting), Preview & Print the Text, Pictures, Images,
Symbols etc. can be inserted between the text.
 Text search, Replacement, Cut/Copy-Paste options are the basic features.
 Spell check, Thesaurus (Dictionary), Mail Merge (to prepare large no. of Call
Letters with recipient name &address change etc.), Tables etc. are very useful
features of the Word processor.
The Interface
1. Spellchecking and Grammatical errors
 Word automatically checks your documents for spelling and/or grammatical
errors.
 clicking Tools > Spelling and Grammar and following the instructions, replacing
wrongly spelt words with recommended ones.
 To change the dictionary e.g. from and English Dictionary into a German
dictionary:
 Tools > Spelling and Grammar > Change dictionary

2. Preview
 To preview your document prior to printing it to ensure that your work is
correctly aligned
 File > Print Preview Or
3. Page Setup
To change the attributes of the page select File > Page Setup
4. Deleting text
To delete text highlight the text and either press the Del key on your keyboard or
else select Edit > Cut.
5. Finding and replacing text
To find text in a document press Edit > Find and key in the word you are looking
for then press Find Next to go through all your document.
6. Page Setup
To modify the page layout from landscape to portrait or vice versa File > Page
Setup and select the orientation that you require.

To change the Page margins select File > Page Setup and change the parameters
of the margins i.e. the left right margins and the gaps at the top and bottom of your text.
7. Changing Fonts, Sizes and Outlines
To change the font, size or outline of any of your selected text you either set the
parameters of the text before you start typing or alternatively you may select the text
and choose the parameters that you require.
8. Alignment
To align text, select the text and then select the icon for the required alignment
9.Table
To create a table select Table > Insert > Table and from the window that appears
select the amount of rows and columns that your table would have

1. 14 PREPARATION OF WORKSHEET
A worksheet is a working paper used by an accountant to organize accounting
information for preparing the financial statements and adjusting entries.
Use of Worksheet
 The worksheet is used to gather information on adjustments and account
balances from the financial statements.
 This helps reduce the chance of error, omission, duplication, and assures
mathematical accuracy prior to the actual preparation of the formal financial
statements.
 The worksheet is useful in preparing interim financial statements.
 The adjustments are reflected on the worksheet only, and not yet recorded in the
journal or ledger accounts.
Worksheet
Normally, a worksheet has 5 sets of double columns:
1. Unadjusted trial balance column: The accounts and their balances are taken
from the ledger and entered in these columns;
2. Adjustments: Adjusting entries are recorded in these columns. The worksheet is
not a journal but a worksheet. It is used only for gathering the adjustment data.
The adjusted trial balance is prepared by combining the adjustments with the
unadjusted balances.
3. Adjusted trial balance: The results of combining the unadjusted trial balance and
adjustments columns are entered here.
4. Income statement: Those accounts that belong on the income statement are
extended from the adjusted trial balance columns to the income statement
columns.
5. Balance sheet and statement of owner’s equity : Those accounts that belong on
these financial statements are extended from the adjusted trial balance into the
last two columns of the worksheet.
STEPS FOR PREPARATION OF WORKSHEET
The procedure for preparing worksheets is as follows.
1. Enter the unadjusted trial balance and ascertain the equality of debits and credits.
If the trial balance is in balance, it suggests accuracy in the accounts, although this
not a guarantee.
2. Enter the necessary adjustments into the two adjustments columns. Be sure that
debits equal credits for each adjustment. It is common practice to use an
identifying letter to relate the debit to the credit of each adjustment. Remember
that the purpose of adjusting entries is to bring the accounts to their proper
balances and to ensure that expenses are recorded in the period that they are
incurred and revenues are recorded when they are earned.
3. Enter the correct amounts in the adjusted trial balance columns by summing the
amounts in the unadjusted trial balance columns with the amounts in the
adjustment columns. The amounts in the adjusted trial balance are the same as
those in the accounts of the financial statements as a check, you should foot the
two adjusted trial balance columns and ensure that total debits still equal total
credits.

4. Extent the adjusted accounts to the income statement or balance sheet columns.
For each item, decide if it is a balance sheet account or an income statement
account. Then copy debit balances to the appropriate debit column and credit
balances to the appropriate credit column.
5. Footing of the income statement and balance sheet columns. There are three
different situations:
 The income statement columns are equal, means that revenues equal expenses
and there is no net income or net loss. In this case there is no change in owner’s
equity.
 The income statement credit column exceeds the debit column. the difference
represents net income for the period.
 The income statement debit column exceeds the credit column, the difference
represents a net loss.
The difference between revenues and expenses is added directly to the statement of
owner’s equity. Net income is added to the retained earnings.
MAIL MERGE
Mail merge is a function in word that lets the user prepares one document that
he would like to send to many recipients whose details are stored in a database (an
application that stores information). To prepare the mail merge follow the given steps
1. Open your letter in Word and then bring up the Mail Merge Sidebar Wizard by
going to Tools > Letters and Mailings > Mail Merge.
2. The sidebar will appear on the right side of the window, next to the Document.
3. Check the ‘Letter’ option from the document type and click Next below the wizard.
4. Select the ‘Use the current document’ check box and click on ‘Next: Select
recipients’ to move on.
5. This step is used to select the data source for the recipient list. Check the ‘Type a
new list’ option to create a new data source list or leave the checked option ‘Use
existing list’ and then click Next. A “Select Data Source” dialog box will appear.
Choose the data source from the existing list and then click open.
6. Mail merge recipient dialog box will appear choose the recipients, and then click
ok.
7. The next part is inserting recipient information from the data source into the Word
document.
8. To do this, first select the place in the document where you want to insert a field
from the data source and click on ‘More items’. Dialog boxes will pop-up, giving you
a list of all of the fields that are possible to insert.
9. Select the field that you want to insert and click ‘Insert’. It will replace the selected
section of text with “«field_name»”
10. Once you have entered all of your merged fields into the correct places and checked
the formatting around them, click on ‘Next: Preview your letters’.
11. We can preview the letters to make sure that everything will look correct once the
records from the data source are merged.
12. Once your merge is set up correctly you can complete it by clicking next ‘complete
the merge’.
13. Next you can choose to either print the letters or view the merge as individual
letters. Either option will bring up the dialog box. You can choose to merge all of

the records in the data source, just the ‘Current record’ that you are displaying in
the preview, or a certain section of continuous records.
14. Selecting ‘Edit individual letters’ will open up a new Word document. In this
document, each page will contain the form letter with one of the records merged
into it.
15. Edit individual letters. For example if we want to add a message to a specific
recipient you can do it in this step.
DATA SOURCE
REGNO SNAME ADDRESS CITY PHNO
13TA0034 ABHI 2,NEW STREET TRICHY 4563668
13TU6703 UMESH 67,2ND CROSS,ST.
ANTONY ST
CHIDAMBARAM 6746783
14TA2356 GANESH 47/B, VANAVILNAGAR, PONDY 7897667
LETTER FORMAT
FROM
HEAD OF THE DEPT.
PONDICHERRY UNIVERSITY
TO
<<REGNO>>
<<SNAME>>
<<ADDRESS>>
<<CITY>>
<<PHONE>>
DEAR STUDENTS,
WISH YOU HAPPY NEW YEAR
BEST WISHES
[HOD]

INFORMATION TECHNOLOGY
Information Technology (IT) refers to the scientific, technological, and
engineering disciplines as well as management technologies used in information
handling, communication, processing, its applications and associated software,
equipment and their interaction.
It includes:
Software applications and operating system, Web-based information and
applications such as distance learning, Telephones and telecommunications, Video
equipment and multimedia products, World Wide Web and Electronic devices such as
photocopiers.
Components of Information Technology
The components of IT include Hardware, Software, data and people.
Role of Information Technology
Information Technology plays a vital role in the contemporary global economy. It
has made a significant impact on research and development. The major areas impacted
by the advent of information technology include business, media, education, and so
forth.
Information Technology in Business:
 Information technology plays an important role in business environment
 In the past few years, rapid development in IT, particularly in communication,
electronic service networks, and multimedia have opened up new opportunities
for corporate.
 All these are contributing towards new and effective ways of processing business
transactions, integrating business processes, transferring payments, and
delivering services electronically.
 Electronic commerce or e-commerce refers to the electronic means to conduct
commerce between business communications and transactions over Internet.
 It includes buying and selling over the Internet, electronic fund transfers, smart
cards, digital cash, and all other ways of doing business over digital networks.
Information Technology in Manufacturing:
 Corporate are developing a manufacturing Society to provide manufacturers,
distributors, and researchers with structured methods and practices for
implementing technologies in manufacturing environments.
 Using IT, simulation systems have been developed, which enable manufacturers
to virtually prepare prototype plant layout, optimise raw material usage, and
assess ergonomic factors prior to investing in plant redesigns or new factories.
Information Technology in Mobile Computing
 Mobile computing is a technology of wireless networking that uses common
frequencies for transmission to permit networked devices move freely within the
broadcast coverage area and yet remain connected to the network.
 Mobile computing enables people to access network services anytime and
anywhere and allow the transmission of data, with the help of computers.

Information Technology in Public Sector
 In recognition of the serious staffing and equipment situation in the public
sector, there is currently a great deal of activity in outsourcing of information
services.
 In countries where public sector is still developing, and is under the control of
government, there is a great requirement to automate services such as booking
of railway tickets and payment of electricity bills.
Information Technology in Defence Services
 Today, military operators are restricted in their access to information. Most
often, military operators use voice over radio or formatted text messages to
communicate during crisis.
 To help the military improve readiness and response, more flexible, timely, and
dependable access to information is needed.
 Key research areas in this field include dialogue management, context tracking,
language generation, input language understanding, and hands-free and eyes-
free interaction.
Information Technology in Media
Print Media: The print media is the most widespread of the all media technologies. It
remains the most widely adopted, portable, flexible, and economical media. The most
common example of print media is paper that includes newspaper and books.
Electronic Media: Despite the growing popularity of the Internet, radio and television
still represent the mode through which people around the world receive information
about national and international events.
Electronic Learning:
E-learning or learning through computer technology is fast becoming an extremely
versatile solution of providing learning with the tools necessary to needs of students in
order to provide good and standardized education.
E-learning Modes Description
Computer-based
Training
CBT is the training where a computer program provides motivation
and feedback in place of a live instructor. It can be delivered
through CD-ROM, LAN or Internet.
Web-based
Training.
WBT is the training, which delivers educational content through a
web browser over the public Internet, or a private Intranet. Web-
based training often provides links to other learning resources
such as references, e-mail, bulletin boards, and discussion groups.
It may also include a facilitator who can provide course guidelines,
manage discussion boards, deliver lectures, and so forth.
Virtual Classrooms:
 This new technology helps captivate the student's interest. This concept
interactivity involves a student with software that reacts and interacts, unlike a
book.

Information Technology in Publication
 In this ever-changing world, publishing houses, universities, and e-book stores
have started to use information written in printed version books on their
computer screen through the use of technology.
 E-texts play an increasing role in education and research, as they offer unique
benefits for both students and teachers.
CAREERS IN INFORMATION TECHNOLOGY
The spread of IT has generated a need for highly trained workers to design and
develop new information systems and to integrate new technologies in them. Some of
career opportunities available in the IT industry are as follows.
Programmer
 A programmer is a person who writes the code for a computer program.
 The programmers write programs, depending on the specifications given by the
systems analysts and software engineers.
 These instructions are coded in a programming language such as C, C++, and
Java.
 There are two types of programmers: application programmers and systems
programmers.
Systems Analyst
 Systems analyst plans, designs, develops, and implements new systems or
applies the existing system resources to perform additional operations. Some
systems analysts are also known as system developers or system architects.
 Systems analyst determines the problem in the system by discussing it with the
managers and users before starting an assignment.
Network Administrator
 A network administrator is a person who installs, configures, and supports the
local area network, wide area network, the Internet system or the segment of a
network system in an organization.
Database Administrator
 A database administrator (DBA) is an individual who is responsible for the
storage of data, management of the database, and implementation of the
database management system.
 DBA is responsible for maintaining data integrity, backup systems and database
security.
Web Designers
 A web designer is an individual who provides an architectural structure for the
effective communication of client’s content by logically organising the
information and making it accessible.
 With the rapid growth of Internet, many jobs relating to design, development,
and maintenance of the websites and servers have cropped up in the market.
Business Process Outsourcing
 Business Process Outsourcing (BPO) refers to assigning to another party some or
all non-core processes.

Introduction to Computers

More Related Content

What's hot (20)

Similar to Introduction to Computers (20)

More from Prabu U (20)

Recently uploaded (20)

Introduction to Computers