The Internet and the World Wide Web

Chapter 2A

The Internet’s History

• 1969 – ARPANET – The seed of internet was planted in 1969, when the Advanced Research Project Agency (ARPA) of US Department of Defense (DoD) began connecting computers. – Connected universities and defense bases – The resulting network was called ARPANET. • 1973 – ARPANET connects to Europe

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Engr. Naveed Jan Page 1 of 19 ARPANET 1973

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The Internet’s History

– National Science Foundation (NSF) joined the project after DoD stopped funding the network – NFS established five super computing centers for academic and research purpose for all – NSF expected the supercomputers users to use ARPNET to obtain access but they discovered that the existing network could not handle the load.

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Engr. Naveed Jan Page 2 of 19 The Internet’s History

• Mid-1980s – NSFNet – NSF created NSFNet – Link between ARPANET, NSFNet and other networks was called internet. – Network between supercomputers – No commercial traffic allowed • 1990s – ARPANET shut down – NSFNet abandoned – Commercial networks take over 2A-5 Today and the Future

• 100,000 new web sites per month • More than 50% of U.S. households online • Access is available throughout the U.S. • Eventually access will be global

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Engr. Naveed Jan Page 3 of 19 U.S. Internet Growth

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The Internet’s Major Services

• The World Wide Web (WWW) • Electronic mail (e-mail) • News • File Transfer Protocol • Chat • Instant Messaging • Online Services • Peer-to-peer services

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Engr. Naveed Jan Page 4 of 19 The Internet’s Major Services

• The World Wide Web (WWW) – According to WWW consortium, The World Wide Web is the universe of network-accessible information, an embodiment (realization) of human knowledge Note: – The Web, as it's commonly known, is often confused with the internet. Although the two are connected, they are different things. – The internet is, as its name implies, a network -- a vast, global network that incorporates a multitude of lesser networks. As such, the internet consists of supporting infrastructure and other technologies. – In contrast, the Web is a communications model that, through HTTP, enables the exchange of information over the internet. 2A-9

The Internet’s Major Services

• The World Wide Web (WWW) – Developed in 1993 by Tim-Berners Lee – Allowed connection of documents – Required a browser to read documents • Electronic mail (e-mail) – Instantaneous transmission of documents

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Engr. Naveed Jan Page 5 of 19 The Internet’s Major Services

• News – Often called newsgroups – Electronic discussions on several topics • File Transfer Protocol (FTP) – Sends and receives files

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The Internet’s Major Services

• Chat – Public real time conversation • Instant messaging – Private real time conversation • Peer-to-peer services – Allows sharing of files among users – Torrents, Napster and Kazaa are examples – Illegal to share copyrighted material

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Engr. Naveed Jan Page 6 of 19 Accessing The Internet

• Internet Service Provider (ISP) – Company that provides Internet access • Dialup – Connects to Internet through phone line – Modem connects to the phone line – Slow connection

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Accessing The Internet

• High-speed access – Connect through a special line – 2 – 25 times faster than dialup – DSL, Cable, T1 are common

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Engr. Naveed Jan Page 7 of 19 What is WWW ?

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Understanding the Internet

Hypertext • Hypertext is text displayed on a computer display or other electronic devices with references (hyperlinks) to other text that the reader can immediately access. Hypertext documents are interconnected by hyperlinks, which are typically activated by a mouse click, key press sequence or by touching the screen Hypertext Transfer Protocol (HTTP) • To support hypertext documentation, the web uses a special protocol called the hypertext transfer protocol. • HTTP is the protocol to exchange or transfer hypertext. Hypertext Markup Language (HTML) • Hypertext Markup Language (HTML) is the standard markup language for creating web pages and web applications. • HTTP and hypertext links are foundation for the WWW

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Engr. Naveed Jan Page 8 of 19 Understanding the Internet

• The Internet allows accessing resources • The Web simplifies the Internet • The Web connects documents – Hypertext creates links between documents – Documents are stored on a web server – HTTP delivers documents

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Understanding the Internet

• Web site is a collection of web pages – Websites are housed on web servers – Pages are published to the web – Publishing is also called posting or uploading. • Hypertext Markup Language – Creates web pages – Describes how pages should look – Content enclosed in tags – content 2A-18

Engr. Naveed Jan Page 9 of 19 Understanding The Internet

• Browsers – Read and translate the HTML – Display web content • Uniform Resource Locator (URL) – Address of a web page

http://www.uotnowshera.edu.pk/admissions/

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Understanding The Internet

• Helper applications – Plug-ins (window media, apples quick time) – Enhance a browser’s functionality • Streaming audio and video – Sends the file in small chunks – Chunks downloaded while others play

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Engr. Naveed Jan Page 10 of 19 Streaming Audio

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Using a Browser And The WWW

• Browser starts on the home page • Navigating the web – Enter a URL in the browser – Click a link called hyperlink ( e.g computer) – Links are typically blue underlined words – Image maps are picture links • When finished, close the browser

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Engr. Naveed Jan Page 11 of 19 Searching the Web

• The Web is unorganized • Directories – Categorize the Internet • Search engines – Find sites by keyword

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Searching the Web

• Site searches – Large sites have an internal search • Metasearch sites – Search several web sites at once • Sponsored links – Sites pay for better search results

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Engr. Naveed Jan Page 12 of 19 Search Techniques

• Quote the exact phrase • Use the keyword AND or OR

• Use the keyword NEAR • Avoid common words • Use the site’s advanced tools

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Chapter 2A

End of Chapter

Engr. Naveed Jan Page 13 of 19 Chapter 2B

E-mail and Other Internet Services

Using E-mail

• Exchanges messages with other users – Messages reach destination in seconds – Mail waits in mailbox until opened – Text, audio, pictures and video messages

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Engr. Naveed Jan Page 14 of 19 Using e-mail

• Configuring e-mail – e-mail clients read and send e-mail – Outlook and Eudora are common • Need name of mail server • Need username and password – Gmail, Hotmail and Yahoo are online clients • No configuration needed

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Using e-mail

• e-mail addresses – Unique address – Allows sending and receiving – [email protected] • Listserv – an application that distributes messages to subscribers on an electronic mailing list. – Lists of e-mail addresses – Each address gets the e-mail

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Engr. Naveed Jan Page 15 of 19 Using e-mail

• e-mail actions – Create a new message – Send an attachment – Reply to e-mail – Open attachments – Forward an e-mail

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Other Internet Features

• News – Public board devoted to a topic – Thousands of topics available – Messages are called threads – Users can create threads – Users can comment on threads – Need a news reader program

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Engr. Naveed Jan Page 16 of 19 Other Internet Features

• File Transfer Protocol (FTP) – Copies files from a remote computer – FTP client is needed – Some sites require a password

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Other Internet Features

• Internet Relay Chat (IRC) – Real time communication system – Multi-users with many channels (rooms) – Channels are dedicated to a topic – All users can read the comments

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Engr. Naveed Jan Page 17 of 19 Other Internet Features

• Instant messaging (IM) – Private, real-time communication – Message sent only to listed users – Buddy lists contain IM names – Windows messenger, AoL messenger etc

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Other Internet Services

• Online services – Company that offers access by subscription – Banks, games and research – America Online offers content and Internet

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Engr. Naveed Jan Page 18 of 19 Other Internet Services

• Peer-to-peer (P2P) services – User computers are connected together – No centralized organization – Users can communicate directly – Users can share files

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Chapter 2B

End of Chapter

Engr. Naveed Jan Page 19 of 19