Lecture-02 - Introduction to computer.pptx

Introduction to
Computer
by Md. Sakhawat Hossain

A computer can be divided into two main categories:
Hardware: The equipment that processes the data to create information is called
hardware. It includes keyboards, mice, displays, system units, and other devices.
Hardware is controlled by software. (Hardware is basically that you can touch with
you fingers)

A computer can be divided into two main categories:
Software: A program consists of the step-by-step instructions that tell the computer
how to do its work. Software is another name for a program or programs. The
purpose of software is to convert data (unprocessed facts) into information
(processed facts).

Data vs Information
Data: The raw, unprocessed facts, including text, numbers, images, and sounds,
are called data.
Information: Information is data that has been organized or presented in a
meaningful. (Processed data yields information)

System Unit
The system unit is a container that houses most of the electronic components that make up a
computer system.

The System Board (Motherboard)

The Central processing Unit (CPU)

Control Unit (CU)
Control Unit of a computer system manages the operations of all components of the
system.

Processor Cores
Core is usually the basic computation unit of the CPU that handles the
Mathematical & Logical operations.
▪ A core can have its own Clock Speed.
Two types –
Single Core Processor
Multi Core Processor

Single Core Processor
A Single Core Processor is a microprocessor with a single core on chip.
It can run a single process at a time.

Multi Core Processor
A Multi Core Processor is a microprocessor with multiple single core on chip.
Dual Core: Two execution cores
Quad Core: Dual Core + Dual Core = Quad Core

Power Trends
Frequency
Voltage
load
Capacitive
Power 2




Memory
Memory is the electronic holding place for the instructions and data a computer
needs to reach quickly.
Two types of computer memory:
▪ Primary Memory (Main Memory)
▪ Secondary Memory (Storage)

Primary Memory (Main Memory)
Primary memory holds only those data and instructions on which the computer is currently
working.
These are semiconductor memories.
Data is lost in case power is switched off.
It is the working memory of the computer.
Faster than secondary memories.

Primary Memory (Main Memory)
There are two types of primary memory -
• Random Access Memory (RAM)
• Read Only Memory (ROM)

Secondary Memory (Storage)
This type of memory is also known as external memory. These are used for storing
data/information permanently. For example, disk, CD-ROM, DVD, etc.
• These are magnetic and optical memories.
• It is known as the backup memory.
• Data is permanently stored even if power is switched off.
• It is used for storage of data in a computer.
• Slower than primary memories.

Hard Disk & Floppy Disk
Hard Disk Floppy Disk

Cache Memory
Cache memory is a very high speed semiconductor memory which can speed up
the CPU. It acts as a buffer between the CPU and the main memory. It is used to
hold those parts of data and program which are most frequently used by the CPU.
Cache memory is faster than main memory.
• It consumes less access time as compared to main memory.
• It stores the program that can be executed within a short period of time.
• It stores data for temporary use.
▪ Cache memory is faster than main memory.

Basic Units of Measurement
(Processor And Memory Speed)

Software
A program consists of the step-by-step instructions that tell the computer how to do
its work. Software is another name for a program or programs. The purpose of
software is to convert data (unprocessed facts) into information (processed facts).
There are two major kinds of software:
System software
Application software

System software
System software is not a single program. Rather, it is a collection of programs, including the
following:
 Operating Systems
 Utilities

Operating System
Smartphones, tablets, and
many other mobile devices
use embedded operating
systems, also known as real-
time operating systems
(RTOS).
Desktop computers use
standalone operating
systems like Windows 10 or
mac OS.
Networks use network
operating systems (NOS).
A network operating System

Operating System
Microsoft Windows
Mac OS
Linux

Utilities Software
Utilities perform specific tasks related to managing computer resources. One of the
most essential utility programs that every computer system should have is an
antivirus program.

Utilities Software
Utilities software is used to remove any problem or solve a complex situation
in computer.
Partition Magic
Backup Utility
Data Recovery
Security software
Antivirus

Application Software
Application software might be described as end-user software. Three types of application
software are
 General-purpose Application
 Specialized Application
 Mobile Application

General-purpose applications are widely used in nearly all career areas. They are the
kinds of programs you have to know to be considered an efficient and effective end user.
Some of the best known are presented in the Figure given below:

Specialized applications include thousands of other
programs that are more narrowly focused on specific
disciplines and occupations. Two of the best known
are graphics and web authoring programs.

Mobile apps, also known as mobile applications or simply
apps are small programs primarily designed for mobile
devices such as smartphones and for tablet computers.

Personal Computer
Personal computers, also known as PCs, are the least powerful, yet the most widely used
and fastest-growing type of computer.
 Desktops
 Laptops
 Tablets
 Smartphones
 Wearables

Tablets
Tablets, also known as tablet computers, are smaller, lighter, and generally less powerful
than laptops. Like a laptop, tablets have a flat screen but typically do not have a standard
keyboard. Instead, tablets typically use a virtual keyboard that appears on the screen and is
touch-sensitive.

Smartphones
Smartphones are the most widely used handheld computers. Smartphones are cell
phones with wireless connections to the Internet and processing capabilities.

Wareable
Other mobile computers include wearable devices like Apple’s Watch, Galaxy
Watch.

Mainframe Computer
Mainframe computers occupy specially wired, air-
conditioned rooms. Although not nearly as powerful as
supercomputers, mainframe computers are capable of
great processing speeds and data storage. For
example, insurance companies use mainframes to
process information about millions of policyholders.

Super Computer
Supercomputers are the most powerful type of
computer. These machines are special, high-
capacity computers used by very large
organizations. Supercomputers are typically used
to process massive amounts of data. For example,
they are used to analyze and predict worldwide
weather patterns. IBM’s Blue Gene supercomputer
is one of the fastest computers in the world.

Midrange Computer
Midrange computers, also referred to as servers, are
computers with processing capabilities less powerful than
a mainframe computer yet more powerful than a personal
computer. Originally used by medium-size companies or
departments of large companies to support their
processing needs, today midrange computers are most
widely used to support or serve end users for such specific
needs as retrieving data from a database or supplying
access to application software.

Lecture-02 - Introduction to computer.pptx

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