Lecture#6

Internet

Internet

• A network of networks, joining many government, university and private computers together and providing an infrastructure for the use of E-mail and other services.

• The largest network of networks in the world.

• Services on Internet:

• Email

• Web

• Chat

• File Transfer

• Instant Messaging etc…

History of the InternetHow has the Internet grown?

Today

More than 150 million host nodes

1984

More than 1,000 host nodes

1969

Four host nodes

Evolution of the Internet

• The Internet originated as ARPANET in September 1969 and had two main goals:

5

Allow scientists at different physical locations to share

information and work together

Function even if part of the network were

disabled or destroyed by a disaster

Evolution of the Internet

1969ARPANET becomes

functional

1984ARPANET has

more than 1,000

individual computers linked as

hosts

1986 NSF connects NSFnet to

ARPANET and becomes

known as the Internet

1995 NSFNetterminates its network

on the Internet and

resumes status as research network

1996Internet2 is

founded

Today More than 550

million hosts connect to

the Internet

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Evolution of the Internet

• Many home and small business users connect to the Internet via high-speed broadband Internet service

Cable Internet service

DSL

Fiber to the

Premises (FTTP)

Fixed wireless

Cellular Radio

NetworkWi-Fi

Satellite Internet Service

Evolution of the Internet

• An access provider is a business that provides individuals and organizations access to the Internet free or for a fee

Evolution of the Internet

ISP (Internetservice provider)

Regional ISPs provide Internet

access to a specific geographical area

National ISPs provide Internet

access in cities and towns nationwide

Online service provider (OSP)

Has many members-only features

Popular OSPs include AOL (America

Online) and MSN (Microsoft Network)

Wireless Internet service provider

Provides wireless Internet access to

computers and mobile devices

May require a wireless modem

Evolution of the Internet

• 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 the domain name into its associated IP address

History of the Internet

Who controls the Internet?

• No onec—cit is a public, cooperative, and independent network

• Several organizations set standards

High-speed

connection

Slow-speed

technology

How the Internet WorksHow can you connect to the Internet?

p. 70 Next

Dial-up accessmodem in your computer uses a

standard telephone line to connect to the Internet

Digital subscriber line (DSL),

cable telephone Internet

services (CATV), cable modem

provide connections using

regular copper telephone lines

Connection is always on—

whenever the computer

is running

Connection must be established

each time you log on.

Slow but inexpensive

The World Wide Web

p. 75

What is the World Wide Web (WWW)?

A worldwide collection of electronic documents

Each electronic document is called a Web page

Also called the Web

Can contain text, graphics, sound, video, and built-in connections

A Web site is a collection of related Web pages

The World Wide WebWhat is a Web browser?

p. 75

MicrosoftInternetExplorer

Netscape

Mozilla

• Program that allows you to view Web pages.

Google Chrome

Safari Opera

The World Wide Web

What is a home page?• The first page that a Web site presents

• Often provides connections to other Web pages

The World Wide Web

What is downloading?

• The process of a computer receiving information

• Depending upon connection speed, downloading can take from a few seconds to several minutes

The World Wide Web

What is a URL?

Unique address for a Web page

• A web server delivers the Web page to your computer

The World Wide Web

• Tabbed browsing allows you to open and view multiple Web pages in a single Web browser window

The World Wide Web

What is a hyperlink (link)?

Item found elsewhere on same Web page

Different Web page at same Web site

Web page at a different Web site

Built-in connection to another related Web page location

The World Wide Web

What is a search Engine?

• Program used to find Web sites and Web pages by entering words or phrases in it.

• These words or phrases called search text

The World Wide Web

What is a hit?

• Any Web site name that is listed as the result of a search

The World Wide Web

• There are thirteen types of Web sites

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Portal News Informational Business/Marketing

Blog Wiki Online Social Network

Educational

The World Wide Web

Entertainment Advocacy Web Application

Content Aggregator

Personal

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The World Wide WebWhat is a portal?A Web site that offers a variety of services from one, convenient

location, usually for free

• Searching, sports, e-mail,

news, weather, auctions,

Web communities

(Web sites that join

people with similar

interests)

The World Wide WebWhat is a news Web site?

p. 82 Fig. 2-13b

• Contains newsworthy material

• Stories and articles relating to current events, life, money, sports, and weather

The World Wide WebWhat is an informational Web site?• Contains factual information

• Created by organizations and government agencies

The World Wide WebWhat is a business/marketing Web site?• Contains content that promotes products• Allows you to purchase products or services online

The World Wide WebWhat is an educational Web site?

Some companies

offer online training

for employees

Some colleges offer

online classes and

degrees

Offers avenues for formal and informal teaching

and learning

The World Wide WebWhat is an entertainment Web site? Offers an interactive environment featuring music,

video, sports, games, and more

The World Wide WebWhat is an advocacy Web site? Contains content that describes a cause, opinion,

or idea

The World Wide Web

• What is an Social Network Web site?

• A Web site that provides a virtual community for people interested in a particular subject, to simply interact together or to increase their circle of friends such as Facebook, MySpace and LinkedIn.

The World Wide WebWiki• A wiki is a website whose users can add, modify, or delete its

content via a web browser using a simplified markup language or a rich-text editor

The World Wide Web• Blog: A Web site on which an individual or group of

users gives opinions, information, etc. on a regular basis.

The World Wide WebWhat is a personal Web site? Web page maintained by private individual

Reasons: sharing life experience with the world

or job hunting

The World Wide Web• A web application is an application that is accessed over a

network such as the Internet or an intranet .The term may also mean a computer software application that is coded in a browser-supported language. Web application is executable in browsers.

The World Wide Web

• Multimedia refers to any application thatcombines text with:

The World Wide Web

• A graphic is a digital representation of nontext information

• Graphic formats include BMP, GIF, JPEG, PNG, and TIFF

The World Wide Web

• A thumbnail is a small version of a larger graphic

The World Wide Web

• Animation is the appearance of motion created by displaying a series of still images in sequence

The World Wide Web

• Audio includes music, speech, or any other sound

– Compressed to reduce file size

• You listen to audio on your computer using a player

• Streaming is the process of transferring data in a continuous and even flow

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The World Wide Web

• Video consists of images displayed in motion

The World Wide Web

• A plug-in is a program that extends the capability of a Web browser

E-Commerce

• E-commerce is a business transaction that occurs over an electronic network

– M-commerce identifies e-commerce that takes place using mobile devices

• Also called Online Shopping.

E-Commerce

E-commerce

Business-to-

consumer (B2C)

Consumer-to-

consumer (C2C)

Business-to-

business (B2B)

Other Internet ServicesWhat is e-mail? Short for electronic mail

The transmission of messages and files via a computer network

Messages can consist of simple text or can contain attachments, such as documents, graphics, or audio/video clips

Internet access providers usually provide an e-mail program

Some Web sites—such as MSN Hotmail and Yahoo!—provide free e-mail services

One of the original services on the Internet

Other Internet ServicesWhat is an e-mail address? Unique name that consists of a user name and domain

name that identifies the user

Other Internet Services

Protocol: A standard set of rules, regulations andrequirements that allow two electronic devices to connect

to and exchange information with one another.

FTP (File Transfer Protocol) is an Internet standard thatpermits file uploading and downloading with othercomputers on the Internet

Many operating systems include FTP capabilities

An FTP server is a computer that allows users to uploadand/or download files using FTP

Other Internet Services

Telnet

• Telnet is a protocol that allows you to connect to remote computers (called hosts) over a network (such as the Internet).

Other Internet ServicesWhat is a mailing list?

Group of e-mail addresses given a single name

When a message is sent to the mailing list, everyone on the list receives the message

To add your name to a mailing list you must subscribe to it; to remove your name you must unsubscribe

Other Internet ServicesWhat is a chat? Real-time typed conversation that takes place on

a computer

Chat room is location on server that permits users to discuss topics of interest

Instant messaging (IM) is a real-time Internet communications service

Other Internet Services

• VoIP (Voice over IP) enables users to speak to other users over the Internet

– Also called Internet telephony