The Internet and the The Internet and the World Wide WebWorld Wide Web

The Internet and the The Internet and the World Wide WebWorld Wide Web

Una Dooney Slide 2 Internet and WWW

What is the Internet?

• This is the physical infrastructure or backbone of computers, cables, satellites

• It is the collection of networks around the world that are able to communicate with each other

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The Global Communications

NetworkSattelites

Computers

Cables

Servers

Users

ISPs

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The Word Wide Web (WWW)

• The WWW is a system that uses Web Addresses (URL’s) to find resources when a user requests them and deliver the files to the user’s computer for viewing

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Surfing the WWW

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The World Wide Web

• It uses Hypertext and Web Browser software to deliver information– The Hypertext is the links we see in

web pages that allow the user to jump from place to place (site to site)

– The Browser is the software used to explore the internet

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Protocols

• The rules to be followed for communication on the Internet

• Some of these:– http (Hypertext Transfer Protocol)– URL (Uniform Resource Locator)– FTP (File Transfer Protocol)– TCP/IP (Transmission Control

Protocol/Internet Protocol)

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URL

• Uniform Resource Locator (URL or Web Address) is made up of a number of parts or protocols

• First, the HyperText Transfer Protocol (http://)

http://http://www.intel.com/pressroom/index.htm

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HTTP• HTTP (Hypertext Transfer Protocol)

– The is the set of rules for exchanging files on the World Wide Web.

– When activated (by mouse-clicking on a link) your request is sent to a web server

– The server handles your request and transfers you to the new location

http://http://www.intel.com/pressroom/index.htm

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Domain Name

• Second, the domain name, the address of the ISP contacted

• (If it is a commercial site, it ends in .com, .org means nonprofit organization). (http://www.kevinmitnick.com)

http://www.intel.comwww.intel.com/pressroom/index.htm

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Paths/Folders

Third, the paths, folders, and file names of sites and their content loaded by the browser

http://www.intel.com/pressroom/index.htmpressroom/index.htm

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FTP: Downloading Files

• The File Transfer Protocol (FTP) is a part of the Internet protocol suite that is able to transfer computer files between machines with widely different operating systems

• This means putting a copy of the file on your computer’s hard drive

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FTP

•All kinds of files - programs, text, graphics, images and sounds - are available to be copied without restriction for non-profit purposes

•Must pay attention to copyright

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TCP/IP

• TCP/IP: (Transmission Control Protocol / Internet Protocol) is a two-layer protocol

• TCP is the Transport (and top) layer

• IP is the Address layer

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TCP

• The purpose is to provide transparent transfer of data between end users

• It manages the breaking down of a message or file into smaller packets that are transmitted over the Internet

• The packets are received by a TCP layer that reassembles the packets into the original message

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TCP

• Not all packages travel the same route to their destination but are routed in the most efficient way to their destination

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IP

• The Internet Protocol, handles the address part of each packet so that it arrives at the right destination

• Each computer connected to the Internet must have an IP address

(127.255.255.255 )

• Domain Names www.itsligo.ie are matched with IP addresses in order to route data

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People

• Tim Berners-Lee– developed the system of hyper-

linking• Mark Andreesen

– developed the first web browser

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The Internet Success Factors

• The emergence of the Internet is due to four factors:– The universal TCP/IP standard– The web-like ability to link from site to

site– The ease of use provided by the

browser’s graphical interface– The growth of personal computers and

their LANs connected to the Internet

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Today

• Millions of computers worldwide are connected to the Internet

• Millions of dollars/euro spent every day online

• Millions of people do business and communicate on it every day

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Uses of Internet

• E-mail and other forms of communication such as Chat Rooms

• Conferencing/Meetings• E-commerce/Shopping• Research/Education• News in real-time