Information Computer Technology (Part II)
- 1. INTERNETAND NETWORK The Internet, also called the Net, is a worldwide collection of networks that links millions of businesses, government agencies, educational institution ns, and individuals. Each of the networks on the Internet provides resources thatadd to the abundanceof goods, services, and information accessible via the Internet. The Internet originated as ARPANET in September 1969 and had two main goals: • Allow scientists at different physicallocations to shareinformation and work together • Function even if part of the network weredisabled or destroyed by a disaster An access provider is a business thatprovides individuals and organizations access to the Internetfree or for a fee • ISP (Internet service provider) • Regional ISPs provide Internetaccess to a specific geographicalarea • National ISPs provideInternetaccess in cities and towns nationwide • Online service provider (OSP) • Has many members-only features • Popular OSPs include AOL (America Online) and MSN (MicrosoftNetwork) • Wireless Internetservice provider • Provides wireless Internetaccess to computers and mobile devices • May requirea wireless modem An IP address is a number that uniquely identifies each computer or device connected to the Internet A domain name is the text version of an IP address • Top-level domain (TLD) A DNS server translates thedomain name into its associated IP address The WorldWide Web, or Web, consists of a worldwidecollection of electronic documents (Web pages) A Website is a collection of related Web pages and associated items A Webserver is a computer that delivers requested Web pages to your computer A Webbrowser, or browser, allows users to access Web pages (InternetExplorer, Mozilla Firefox, Google Chrome, Opera, Safari) A home page is the firstpage that a Web site displays Web pages provide links to other related Web pages Downloading is the process of receiving information • Some Web pages are designed specifically for microbrowsers A Web page has a unique address called a URL or Web address Two types of search tools are search engines and subjectdirectories • Searchengine - Finds information related to a specific topic • Subject directory - Classifies Web pages in an organized set of categories Multimediarefers to any application that combines text with: • Graphics - A graphic is a digital representation of nontext information • Graphic formats include BMP, GIF, JPEG, PNG, and TIFF
- 2. • A thumbnail is a small version of a larger graphic • Animation- Animation is the appearanceof motion created by displaying a series of still images in sequence • Audio- Audio includes music, speech, or any other sound – Compressed to reducefile size – You listen to audio on your computer using a player • Video consists of images displayed in motion • Virtual reality (VR) is the useof computers to simulate a real or imagined environment that appears as a three-dimensional space A plug-inis a programthat extends the capability of a Web browser Web publishing is the development andmaintenance of Web pages E-commerce is a business transaction thatoccurs over an electronic network - M-commerce identifies e-commerce that takes place using mobile devices E-mail is the transmission of messages and files via a computer network An e-mail programallows you to create, send, receive, forward, store, print, and delete e-mail messages A mailing list is a group of e-mail names and addresses given a single name – Subscribing adds your e-mail name and address – Unsubscribing removes your name Instant messaging (IM) is a real-time Internetcommunications service A chat is a real-time typed conversation that takes place on a computer A chat room is a location on an Internetserver that permits users to chat with each other Netiquette is thecode of acceptable Internetbehavior A network is a collection of computers and devices connected together, often wirelessly, via communications devices and transmission media. A network is a collection of computers and devices connected together via communications devices and transmission media When a computer connects to a network, it is online. Advantages of a network include: • Facilitating communications • Sharing hardware • Sharing data and information • Sharing software • Transferring funds A local area network (LAN) is a network that connects computers and devices in a limited geographical area
- 3. A wireless LAN (WLAN) is a LAN that uses no physical wires A metropolitan area network (MAN) connects LANs in a metropolitan area A wide area network (WAN) is a network that covers a large geographicalarea The design of computers, devices, and media on a network is sometimes called the network architecture Client/server network Peer-to-peer network P2P describes an Internet network on which users access each other’s hard disks and exchange files directly over the Internet A network topology refers to the layout of the computers and devices in a communications network Star network Bus network Ring network A communications device is any type of hardware capable of transmitting data, instructions, and information between a sending device and a receiving device • A digital modem sends and receives data and information to and from a digital line • A wirelessmodemuses thecell phonenetworkto connectto the Internetwirelesslyfrom a notebook computer, a smart phone, or other mobile device • A network card enables a computer or device to access a network • A wireless access point is a central communications device that allows computers and devices to transfer data wirelessly among themselves or to a wired network • A router connects multiple computers or other routers together and transmits data to its correct destination on a network • A hub or switch connects several devices in a network together