The Internet THE PHYSICAL ENTITY: A NETWORK OF COMPUTERS IM VoIP FTP P2P WWW

1.Recognize the importance of the Internet. 2.Compare types of Internet connections. 3.Compare popular Web browsers. 4.Demonstrate how to navigate the Web. 5.Discuss how to evaluate the credibility of information found on the Web. 6.Identify the certifications and careers related to the Internet.

Internet Introduction Key Definitions:Key Definitions: –Internet: The internet is a global network of interconnected networks, connecting private, public and university networks in one unit. –Intranet: An intranet is a private enterprise network that uses internet and web technologies for information gathering and distribution within an organization. –Extranet: An extranet is a community of interest created by extending an intranet to selected entities external to an organization.

What is the Internet? A Network of Computer Networks –Started as early as the 1960s –Built to work even if a large part of the network fails Intranet is not the same as Internet Decentralized Client – Server model Supported by various gateways and high speed backbone connections.

Internet Network Internet Network T3 Backbone T3 Backbone T3 Backbone

Brief History of the Internet 1960s - Department of Defense initiative ARPANET ARPA launches the Internetting Project to explore the possibilities of linking networks 1980 – First Virus halts the Internet 1984 – DNS Introduced (Names rather than numbers) 1999 – Internet Banking

Internet Connection To connect to the Internet, you need an Internet service provider (ISP). An ISP can be any one of the following types: Dial-up Broadband Wireless Wireless mobile Satellite

Internet Connection: Wired Dial-up Broadband Options CableDSLFiOS Least expensive Use regular phone line to connect to network $10-$30 per month Very slow, maxing out at 56 Kbps Offered by your cable TV provider Cable speeds range from 1 Mbps – 50 Mbps Uses telephone line to carry digital signal Average speeds of 384 Kbps – 7 Mbps Fastest of the three broadband alternatives Speeds top out at 50 Mbps Can carry Internet, phone, and TV over fiber optic cables

Internet Connection: Wireless Wireless Options WiMax MobileSatelliteMunicipal WiFi Includes 3G and 4G services that connect to the Internet via cellular networks More global and more expensive option Considered when other options are not available Offered in some cities and towns

Internet Connection Using Your Mobile Devices Smartphones Cell phones PDAs Video game consoles (Xbox, Wii, PS3) Portable media players (iTouch, iPod, iPad) eBook readers (Kindle, Nook) Satellite phones

How to access the Internet? Many schools and businesses have direct access to the Internet using special high- speed communication lines and equipment. Students and employees can access through the organization’s local area networks (LAN) or through their own personal computers. Another way to access the Internet is through Internet Service Provider (ISP).

Internet Service Provider (ISP) A commercial organization with permanent connection to the Internet that sells temporary connections to subscribers. Examples: STC Online, Microsoft network, AT&T Networks.

Who owns the Internet? The I nternet C orporation for A ssigned N ames and N umbers ( ICANN ) oversees registrations. InterNIC—central service to reserve domain names (lots of issues arising with “cyberquatting…” Whois – domain name lookup

Services through the net Major services: – – Electronic Mail –FTP – File Transfer Protocol –Gopher –Newsgroups –Telnet – Remote session –WAIS – Wide Area Information System –WWW – World Wide Web

Uniform Resource Locators The IP address and the domain name each identify a particular computer on the Internet. However, they do not indicate where a Web page’s HTML document resides on that computer. To identify a Web pages exact location, Web browsers rely on Uniform Resource Locator (URL). URL is a four-part addressing scheme that tells the Web browser:  What transfer protocol to use for transporting the file  The domain name of the computer on which the file resides  The pathname of the folder or directory on the computer on which the file resides  The name of the file

Structure of a Uniform Resource Locators protocol Domain name pathname filename http => Hypertext Transfer Protocol

Part of a URL PROTOCOL TOP-LEVEL DOMAIN (TLD) THIRD-LEVEL DOMAIN DOMAIN NAME or SECOND-LEVEL DOMAIN

HTTP The transfer protocol is the set of rules that the computers use to move files from one computer to another on the Internet. The most common transfer protocol used on the Internet is the Hypertext Transfer Protocol (HTTP). Two other protocols that you can use on the Internet are the File Transfer Protocol (FTP) and the Telnet Protocol

How to read an URL http = the protocol www = the host computer or server name blast = third level domain ncbl = second level domain org = top level domain dcs = directory name proposal= file name htm = file type / extension

Getting a Domain Name? Top Domains: –edu – Educational Institutions –com – Company / Commercial Organizations –org – Non-profit Organizations –net – Network, network of sites –mil – Military Installations –gov – Government sites Sub Domains: –in - India –jp - Japan –uk – United Kingdom

Identifying a PC on the Internet IP Number – – (Intranet, Local IP) To find your IP number on Windows –Execute ipconfig on your command prompt – XP – winipcgf - 98

Bandwidth Speed of data transfer through the network Access through: –28.8 bps (bits per second) modem –56.6 modem –ISDN –T1/T3 – High speed –Cable –DSL

HTML: Hypertext Markup Language, the authoring language that defines the structure of Web pages Web browsers: Programs that interpret the HTML and display the Web pages Web Browsers

Internet Explorer Mozilla Firefox Google Chrome Apple Safari Released in 1995 Leading Web browser Included with Windows Released in 2004 Similar in look to IE Free and easy to install Released in 2008 Streamlined interface, similar to IE and Firefox Main focus is on speed; Web pages do load faster Not as many features as IE and Firefox Most popular browser for Macs Bundled with Mac OS X and also available for Windows Neat feature is Top Sites preview

Sometimes called microbrowsers IE, Firefox, Safari, and Opera come in mobile versions Kindle, Android, and BlackBerry use proprietary mobile browsers Mobile Browsers

Two ways to navigate: 1.Type the URL (uniform resource locator) Web page address 2.Follow embedded links in the Web pages Website: Consists of one or more Web pages Home page: The main or starting page Ways to Navigate

ICANN (Internet Corporation for Assigned Names and Numbers): Coordinates the Internet naming system IP (Internet Protocol): A unique numbered address associated with a Website, like DNS (Domain Name System): The service that uses a friendly name instead of an IP address to contact a Website The Web Address

Internet ServicesDirect Communication Online Conferencing Distributed Information Resources File Transfer

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