WHAT IS THE INTERNET ?

• A network of networks, joining many government, university and private computers together and providing an infrastructure for the use of E-mail, bulletin boards, file archives, hypertext documents, databases and other computational resources

• The largest network of networks in the world.• Uses TCP/IP protocols and packet switching .• Runs on any communications substrate.

From Dr. Vinton Cerf, Co-Creator of TCP/IP

WHAT IS THE INTERNET ?

BRIEF HISTORY OF THE INTERNET

• 1968 - DARPA (Defense Advanced Research Projects

Agency) contracts with BBN (Bolt, Beranek & Newman) to create ARPAnet

• 1970 - First five nodes: – UCLA– Stanford– UC Santa Barbara– U of Utah, and – BBN

• 1974 - TCP specification by Vint Cerf• 1984 – On January 1, the Internet with its 1000 hosts

converts en masse to using TCP/IP for its messaging

TCP/IP • The Internet protocol suite is the

networking model and a set of communications protocols used for the Internet.

• TCP/IP provides end-to-end connectivity specifying:– How data should be formatted– Addressed,– Transmitted,– Routed – Received at the destination.

IP ADDRESS• IP (Internet Protocol) address: numerical address

given to each computer connected to the network.– An IP address consists of 4 numbers– (ranging from 0 to 255) separated by periods.

• Examples:–128.95.1.207–209.131.36.158–4.2.2.1

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Domain Name System (DNS)

• Remember IP address if you want to request information from another computer

• Domain name: human-readable name given to a related group of networked computers.

• Domain Name System (DNS): hierarchical naming system for computers connected to the Internet

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INTERNET DOMAIN HIERARCHY

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tracer.cs.washington.edu

General

Specific

top-level domain

TOP LEVEL DOMAIN• top-level domain: last part of domain name

– Examples:• .com (commercial)• .org (organization)• .edu (education)• .gov (government)• .uk (United Kingdom)• .ca (Canada)

• Some top-level domains (e.g., .com and .org) are open for registration to anyone, whereas others (e.g., .gov and .edu) have rules restricting eligibility.

• List of top-level domains: – http://www.iana.org/domains/root/db/

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Generic domain labels

Geographic Structure• Geographic TLDs used for organizations in other

countries:

– .uk United Kingdom – .fr France – .ch Switzerland – .jp Japan – .my Malaysia– .sg Singapore– .id Indonesia– .th Thailand– .ph Philiphines

INTERNET SERVICE

Electronic Mail (e-mail)

World Wide Web

File Transfer Protocol (FTP)

Telnet

Internet Telephone

Web TV/Radio

Internet Relay Chat

News Group

Electronic Mail (e-Mail)

• Distributes e-mail messages and attached files to one or more electronic mailboxes.

• Eg:- e-mail addresses– thomas@mes.edu.in – murugan@mesmarampally.org

Electronic Mail (e-Mail)

thomas @ mes . edu .in

murugan @ mesmarampally .org

Continue……

Organization Type of OrganizationName of Person Country

Electronic Mail (e-Mail)

• Different e-mail service providers

– G-Mail– Yahoo Mail– Hot Mail

Continue……

World Wide Web (W W W) / WEBSITE

• Most important service provided by Internet.

• An internet-based hypermedia initiative for global information sharing.

Definitions

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HTML – HyperText Markup Language – The Language of Web Pages on the World Wide Web. HTML is a text formatting language.

URL – Uniform Resource Locator.

Browser – A software program which is used to show web pages.

Tim Berners-Lee• Father of W W W.

• The inventor of HTML.

• Invented W W W while working at CERN, the European Particle Physics Laboratory.

Types of Web Sites

Portal• Offers a variety of Internet services.

• Examples of services:– News– Sports– Search engine/directory– Web publishing– Reference tools– Maps– Shopping– Email

• Examples of portals:– AltaVista, AOL, Lycos, MSN, Netscape, Yahoo!

News

• Contains newsworthy material• Contain stories and articles related to some of

the following:– Life, money, current events, weather

• Examples:– WSB-tv– NBC.com

Informational• Contains factual information• Government agencies provide this type of info:

– Census data, tax codes, congressional budget

• Others that provide this type are:– MARTA– Medicare

Business/Marketing

• Promotes or sells a product• Many examples

Educational

• Offers exciting, challenging avenues for formal and informal teaching and learning.

• Online training for a new skill.• Online courses.• Online college classes.• Examples

– UGA– Phoenix University

Entertainment

• Interactive and engaging• Offer music, video, games, sports, chats,

sweepstakes

Advocacy

• Describes a cause, opinion, or idea• Presents views of a group of people or

organizations

Blog• Short for webblog• Time-stamped articles or posts, in a diary type

format• Vblog – a blog that contains video• Blogosphere – worldwide collection of blogs• Vlogosphere – all vblogs worldwide• Reflect interest, opinions and personalities of the author

Wiki

• Allows user to create, add, modify, or delete web site content.

• Collect recent edits on a web page so someone can review them for accuracy.

• Anyone can modify a wiki.

• Most popular - Wikipedia

Online Social Networks• Encourages members in the group to share interest,

ideas, stories, photos, music, and videos with other users

• Popular examples:– Facebook– MySpace (12 million visitors a day)

• Media Sharing Web site – different– Allows members to share photos, music, and videos– ShutterFly, Flickr – popular sites– GoogleVideo and YouTube are example for video

sharing sites

Personal

• Private individual or family created.

• People publish personal web pages for a variety of reasons:– Job hunting– Share personal experiences– Family histories

Telnet• Allows a user to run commands and programs

remotely on another computer across the Internet.

• The user runs a Telnet client program on the local host.

• A Telnet server process must be running on the remote host.

• The user must have the necessary permissions and password to access the remote host

File Transfer Protocol (FTP)• Protocol for copying files between client and an FTP server.

• Uses a TCP connection for reliable transfer of files with error-checking.

• Most browsers support FTP, or you can use a dedicated FTP client program, e.g WS_FTP.

• Trivial File Transfer Protocol (TFTP) is a lightweight version for small memory devices

What is IRC?– IRC (Internet Relay Chat) is a virtual meeting place

where people from all over the world can meet and talk; you'll find the whole diversity of human interests, ideas, and issues here, and you'll be able to participate in group discussions on one of the many thousands of IRC channels, on hundreds of IRC networks, or just talk in private to family or friends, wherever they are in the world.

Logging Chat

• IRC Client Logs

Web Browser• A web browser or Internet browser is a software

application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier (URI) and may be a web page, image, video, or other piece of content.[1] Hyperlinks present in resources enable users to easily navigate their browsers to related resources.

Browsers• Netscape Navigator (Communicator)

– Product of Netscape (Now owned by AOL)– Originally was dominant– Multi-platform (all operating systems)

• Internet Explorer– Product of Microsoft– Current Dominant Browser– Not available for all operating systems

• Browser compatibility problems can cause web page problems

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Netscape Search

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Netscape Search• 1: Access to

different search engines

• 2. Type words or phrases into text entry box

• 3. Click Button• 4. Preserve favorite

search engine

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Internet Explorer Search

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•Separate Panel In Browser

•Uses MicroSoft Network search

Search Engines

• For searching information on the Internet.

– Google– Yahoo– Altavista

WIKIPEDIA

• A wiki is a publishing platform on which many people can contribute new content and revise existing content.

• The content benefits from the collective knowledge of the contributors, so wikis can be very beneficial for group projects.

• Some businesses and organizations use wikis to maintain documents.