The Internet andWorld Wide Web

Objectives

Discuss how the Internet works

Understand ways to access the Internet

Identify a URL

Describe the uses of e-commerce

Identify the tools required for Web publishing

Explain how e-mail, FTP, newsgroups and messageboards, mailing lists, chat rooms and instantmessaging work

The Internet or the Net

A collection of computers and other devices connected together via communicationsModemsCablesTelephone linesSatellites

A worldwide collection of networks that links millions of businesses, government agencies, educational institutions, and individuals

message board

instant messaging

file transfer

e-mail

Web

The Services on the Internet

chat

History of the InternetAPRANET

ARPANET: Networking project by Pentagon’s Advanced Research Projects Agency (ARPA)

Goals: To allow scientists at different locations to

share information and work together on military and scientific projects

To function even if part of the network were disabled or destroyed

Became functional in 1969

ARPANETA host node or a host

Any computer that directly connects to a network

Often stores and transfers data and messages Provides network connections for other

computers Four original nodes on ARPANET

UCLA UC – Santa Barbara Stanford Research Institute University of Utah

How has this network grown?

1969: Four host nodes

1984: More than 1,000 host nodes

2004: More than 100 million host nodes

What is NSFnet?

The National Science Foundation’s network

Five supercomputer centers

Connected to ARPANET in 1986

NSFnet + APRANET = The Internet

Who provides the structure forthe Internet today?

Networks from corporations, commercial firms, and other companies

Telephone companies

Cable companies

Satellite companies

Government

Who controls the Internet?

The Internet is a public, cooperative, and independent network

No single entity controls or owns the Internet

Several organizations advise and define standards W3C – oversees research and sets

standards and guidelines Internet 2 – develops and tests advanced

Internet technologies

Internet service provider (ISP)

A business that has a permanent Internet connection

Provides temporary connections to individuals and companies for free or for a fee

Regional ISP - Provides access to the Internet through one or more telephone numbers local to a specific geographic location

National ISP - Provides local telephone numbers in most major cities and towns nationwide

How can you connect to the Internet?

High speed connectionConnect to service provider through a high-speed connection line leased from local telephone company

Dial-up accessComputer, modem, regular telephone lineDial into an ISP

Newer high-speed technologies

DSLCable modem

Backbone• Inner structure

of the Internet• Communications

lines that carry the heaviest amount of traffic

Three parts of an Internet connection

Server• Computer that

manages the resources on a network

• Provides a centralized storage area for resources

• Also called a host computer

Client• Computer

that can access the contents of the storage area on the server

Internet protocol (IP) address

Number that uniquely identifies each computer or device connected to the Internet

Four groups of numbers, each separated by a period

Number in each group is between 0 and 255

199.95.72.10

What is a domain name?

Text version of an IP address

Components are separated by periods

Each domain name represents one or more IP addresses

199.95.72.10

www.course.com

A top-level domain (TLD) abbreviation

Identifies the type of organization associated with the domain

Sometimes called dot com when TLD is com

Internet Corporation for Assigned Names and Numbers (ICANN)

Group that assigns and controls TLDs

What systems control domain names?

Domain name system (DNS)

stores the domain names and their corresponding IP addresses

DNS server

Translates the domain name into its associated IP

address

World Wide Web (WWW) or the Web

A worldwide collection of electronic documents

Each document on the Web is called a Web page

Can contain text, graphics, sound, and video

Can contain built-in connections to other documents

A Web site is a collection of related Web pages

What is a Web browser?

Software program that allows you to access and view Web pages

Some popular browsers

Firefox (47.4%)

Internet Explorer (39.3%)

Chrome (7%)

Safari (3.3%)

What is downloading?

The process of receiving information, such as a Web page, onto your computer

from a server on the Internet

Can take from a few seconds to several minutes

What is a hyperlink?

Also called a link Built-in connection

to another related Web page or part of a Web page

Allows you to obtain information in a nonlinear way

How can you identify a link?

Link can be a word, phrase, or image

Text links usually are underlined or in a color different from the rest of the document

A graphical link may change its appearance when you point to it

The shape of the pointer on the screen changes to a small hand with a pointing index finger when you position it on a link or point to the link

Click the link to activate it

Uniform Resource Locator (URL)

Browser retrieves a Web page by using the URL Also called a Web address

http://www.nationalgeographic.com/travel/index.html

address text box

address text box

What are the parts of a URL?

protocol domain name path

Click to view Web Linkthen click URLs

http://www.nationalgeographic.com/travel/index.html

p. 2.13 Fig. 2-10

Next

filename

What is a search engine?

A software program you can use to find Web sites, Web pages and Internet files

What is a portal Web page

Often called a portal

Offers a variety of Internet services from a single, convenient location

maps

stock quotes

reference tools

sports and weather

search engine

What services are often found on a portal?

local , national, and

worldwide news

free personal

Web pages

e-mail

instant messaging

calendars

shopping malls and auctions

newsgroups or message

boards

chat rooms

A Graphic on the WebA digital representation of information such as a drawing, chart, or photograph

What is audio? What is MP3?

Music, speech, or any other sound

A popular technology that compresses audio

Reduces an audio file to about one-tenth of its original size

Streaming audio

enables you to listen to the sound as it downloads

What is video?

Consists of full-motion images that are played back at various speeds

Most video also has accompanying audio

MPEG standard:Video files that you must download completely before you can play them on the computer

Streaming video: allows you to view live video images as they download RealVideo Windows Media Player

What is electronic commerce?

A business transaction that occurs over the Internet

B2C: Sale of goods to the general public

B2B: Businesses providing goods and services to other businesses

What are some features ofe-commerce?

Electronic storefront The place where a customer visits an

online business Shopping cart

Allows the customer to collect purchases

Web page authoring

HTML (hypertext markup language) A set of special codes that format a

file for use as a Web page Created with either:

Word processing package Web page authoring software

What is a plug-in?

An additional program that extends the capability of a browser

Upload, or copy, the site to the

Web server

Locate a Web server to store your site

• Provided by many ISPs at no additional cost

• Provided by a Web hosting service for a monthly fee

How do you deploy a Web site?

What is e-mail?

The transmission of messages and files via a computer network

Use an e-mail program to work with messages

create

receive

store print

sendforward

delete

What is File Transfer Protocol (FTP)?

An Internet standard that allows you to upload and download files with other computers on the Internet File Transfer Protocol

What is instant messaging (IM)?

A real-time Internet communications service

Notifies you when one or more people are online

Allows you to exchange messages or files or join a private chat with them