2nd lecture final internet

8/10/2019 2nd Lecture Final Internet

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Computer networks

Computer network

connects two or

more computers.

The computers can

be geographically

located anywhere


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LAN (local area network)

MAN (Metropolitan area network)

WAN (Wide area network)

PAN (personal area network)

Types of Network


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LAN

Network in small geographical Area(Room, Building or a Campus) is calledLAN (Local Area Network)

A network of computers located in the

same building or a handful of nearbybuildings

Example: Computer network of a University campus


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MAN

Network in a City is call MAN (Metropolitan

Area Network)

that is connect the LAN within the city.


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WAN

A network in which computers are separated by greatdistances, typically across cities, countries or even

continents May consist of several interconnected LANs

Example:

The network connecting the ATM of a banklocated in various cities

Internet


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PAN

Home Networks Connects multiple computers in your home

Share Internet access

Share peripherals

Can be wired or wireless


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Internet

Worldwide group of connected networks that allow

public access to information and services.

No single organization owns or controls

Estimated over one billion users

Variety of users


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The Benefits of Computer

Networks in Education Sharing of computer hardware, software,

and data resources

Unlimited educational resources

Communicate with other educators and

students


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What Is the Internet?

Worldwide group of connected networks

that allow public access to information and

services

No single organization owns or controls

Estimated over one billion users

Variety of users


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What Is the Internet?

The worlds largest network is the Internet, which is aworldwide collection of networks that link together millions

of businesses, governments, educational institutions, and

individuals.


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The InternetWhat are some services found on the Internet?

Next

4. Chat

(4)

(1)

1. E-mail

(2)

2. Web

(3)

3. File transfer

(5)

5. Message board

(6)

6. Instant messaging


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History of the InternetHowdid the Internet originate?

Nextp. 68

Becamefunctional

September 1969

ARPANET

Networking project by

Pentagons Advanced

Research Projects

Agency (ARPA)Goal:

To allow scientists

at different

locations to share

information


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History of the Internet

Started as a network of four computers at

the University of California at Los Angeles

in 1969

Advanced Research Projects Agency

(ARPA) - ARPANET

More than 200 million computers today

Backbone first provided by National

Science Foundation (NSF) - NSFnet


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Backbone now provided by variety ofcorporations

Various organizations help define

standards Internet 2.0

Extremely high-speed network

Develop and test latest Internet technologies Members include over 190 universities in the

United States, along with 60 companies andthe United States government


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History of the InternetHowhas the Internet grown?

Today

More than 150 million host nodes

1984

More than 1,000 host nodes

1969

Four host nodes

Next


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Next

No onecit is a public, cooperative, and

independent network Several organizations set standards

Who controls the Internet?


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High-speed

connection

Slow-speed

technology

How the InternetWorksHow can you connect to the Internet

?

p. 70 Next

Dial-up accessmodem in yourcomputer uses a

standard telephone lineto 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


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How the InternetWorks

Data is divided into packets

Routers send packets across the Internet

Packet switching (breaking info intoindividual packets for best routetransmission)

Transmission control protocol/Internet

protocol (TCP/IP) is the communicationsprotocol used by the Internet


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How the Internet Works


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Internet Service Providers (ISPs), Online Service

Providers (OSPs), and Wireless Internet Service

Providers (WISPs)

Permanently connected to the Internet and provide

connections to individuals and companies for a fee

Regional ISPs provide access in limited

geographical areas, using slow-speed dial-up

Online service providers, such as AOL and MSN

offer members-only services for an added fee

National ISPs provide access in cities and towns,

often through high-speed cable or DSL

Wireless ISPs service mobile computers/devices


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Connecting to the Internet

Business or school network connected to theInternet

Dial-up access ISDN

Cable TV (CATV)

Digital subscriber line (DSL)

Power line communications (PLC)

Public Internet access point


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The Internet Backbone

Acts as a highway

National ISPs use dedicated lines to

connect directly to the Internet

Regional ISPs connect through leased

lines to national ISPs


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Internet Addresses

Numeric addresses

Domain name

Domain type abbreviations

Country code abbreviations


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The World Wide Web

p. 75 Next

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


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The World Wide Web

Hyperlinks Uniform Resource

Locator (URL)

Hypertext transferprotocol (http://)


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The World Wide WebWhat is a Webbrowser?

p. 75 Next

Microsoft

Internet

Explorer Netscape

Mozilla

Program that allows you to view Web pages


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The World Wide Web

Web BrowserSoftware

Mosaic

Netscape Navigator Microsoft Internet

Explorer

Mozilla Firefox

Micro browsers


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The World Wide Web

Searching forInformation on theWeb Directory maintained

by a search enginecompany

Helps to findinformation on the

Web Search engine

Subject directory

The World Wide Web


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The World Wide WebHow can you establish a connection and start the Web

browser?

Step 2.If necessary,

connect to the

Internet

Step 3.Connection to the

Internet occurs, and a

home page displays

Step 1.Click the Web browser

program name

Next


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The World Wide WebWhat is a home page?

Next

The first page that a Web sitepresents

Often provides connections to other Web pages


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The World Wide Web

How do handheld computers and

cellular telephones access the Web?

Use a micro browser

that displays Web pages

that contain mostly text

Must be Web-enabled

Next


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The World Wide Web

What is downloading?

Next

The process of a computer receiving information

Depending upon connection speed, downloading can take

from a few seconds to several minutes


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The World Wide Web

What is a

URL?

Next

Unique address for a

Web page

A webserverdelivers

the Web page to yourcomputer


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The World Wide Web

What is a hyperlink (link)?

Next

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


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The World Wide WebHow can you recognize links?

Next

A link can be textor an image

Pointer changes to a small hand

when you point to

a link

Text links are

usually underlined

and in a differentcolor


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The World Wide Web

What is a search

engine?

Next

Program used to findWeb sites and Web

pages by entering

words or phrases

called search text

Also called a

keyword


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The World Wide WebWhat is a hit?

Next

Step 1.Go to search engine

Step 2.Select type of

search you want

to run

Step 4.Click

link to view

Web site

Step 3.View hits

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


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Types of Web sites

PortalNews

Informational

Business/marketing

Educational

Entertainment

Advocacy

Personal

Next


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Blogs

Books

WikisSocial networks

Types of Web sites


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The World Wide Web

What is a portal?

Next

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)


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The World Wide Web

What is a news Web site?

Next

Contains newsworthy material

Stories and articles relating to current events, life,

money, sports, and weather


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The World Wide WebWhat is a business/marketing Web site?

Next

Contains content that promotes products

Allows you to purchase products or services online


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The World Wide Web

What is an educational Web site?

Next

Some companiesoffer online training

for employees

Some colleges offer

online classes anddegrees

Offers avenues for formal and informal teaching

and learning


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The World Wide WebWhat is an entertainment Web site?

Next

Offers an interactive environment featuring music,

video, sports, games, and more


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The World Wide WebWhat is an advocacy Web site?

Next

Contains content that describes a cause, opinion,

or idea


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The World Wide WebWhat is a personal Web site?

Next

Web page maintained by private individual

Reasons: sharing life experience with the world

or job hunting


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The World Wide Web What is a Blog web site?

A blog(a blend of the term web log) are interactive

sites.

Maintained by an individual updated with regularentries of commentary, descriptions of events, or other

material such as graphics or video.

Allows visitors to leave comments and even message

each other

Example:

Twitter


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The World Wide Web

What is a Book Web site?

Facilitates you to search for the books

from the internet.

Example:

Cyber libraries


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The World Wide Web

What is a Wiki Web site?

Allows users to create, edit, modify or

delete the website content.

Most wikis are open top midification by

general public.

Collects recent edit on web pages so that

one can review them for accuracy.

Example:

Wikipedia


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The World Wide Web

What is a social network site?A social structure made up of individuals which are

connected by one or more specific types of relations,

such as

friendship

kinship

common interest

financial exchange,relationships of beliefs or knowledge

Example:

Face Book


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Other Internet ServicesWhat is e-mail?

Next

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/videoclips

Internet access providersusually provide an e-mailprogram

Some Web sitessuch as MSN Hotmail and Yahoo!

provide free e-mail services


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Other Internet ServicesHow do you send an e-mail message?

Step 1.Start an e-mail

program

(Microsoft

Outlook, for

example)

Step 2.Click the New Mail Message button

Step 3.Enter the recipients

e-mail address, the

subject, and the

message

Step 4.Click the Insert file button if

you want to attach a picture, for

example, and click Send

Step 5.The recipient opens the

message

Next


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Other Internet ServicesWhat is an e-mail address?

Next

Unique name that consists of a user nameand domain

name that identifies the user


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E-mail Primary communication method for

both personal and business use

One of the original services on theInternet

Allows one to create, send, receive,forward, store, print or deletemessages

E-mail programs

Mailbox Mail server

E-mail address

User name @

Domain name

Other Internet Services


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Other Internet ServicesWhat is FTP?

Next

File Transfer ProtocolInternet standard that allows

you to upload and download files with other

computers on the Internet


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FTP (file transferprotocol) FTP server allows

file downloads &

uploads FTP site containstext, graphics,audio, video &program files

FTP allows down load ing f rom or

uploading to a server



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Other Internet ServicesWhat is a mailing list?

Next

Group of e-mailaddresses given a singlename

When a message is sentto the mailing list,everyone on the listreceives the message

To add your name to a mailinglist you must subscribeto it; toremove your name you mustunsubscribe


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Newsgroups Online area in which users conduct written

discussions about a particular subject

Usenet (collection of all Internet newsgroups)

News server (computer storing newsgroup msgs)

Newsreader (program used to access newsgroup)

Article (a previously entered message)

Posting (adding an article to the newsgroup)

Threaded discussion (initial and related articles)

Message board (discussion board; easier to use)

Blog (short for Web log; regularly updated journal)



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Message Boards (Discussion Boards)



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Mailing Lists Group of e-mail names and addresses given a single

name

Subscribe - Adding name to newsgroup/mailing list UnsubscribeRemoving name from the list

LISTSERVsPopular software programs that

manage mailing lists (esp. educational lists)

Newsgroup versus mailing list Newsgroup uses a newsreader for discussions

Mailing list uses email for discussions



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Chat Rooms

Real-time typed conversation via computers

Chat rooms (the channel or medium)

Chat clients (program used to connect to achat server)

Normally included on a browser

Freely downloaded from the Web Some are text-only; others support voice &

video



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InstantMessaging (IM) Notifies you when

one or more people

are online Allows exchange of

messages and files

Allows you to join a

private chat room



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Internet telephony

Also called Voice over IP or VOIPEstimate of five

million subscribers

by 2007


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Telnet Content streaming

Shopping on web (E-Commerce)

Distance learning



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Netiquette Internet etiquette

Code of acceptablebehaviors for Internet user

Examples

Avoid flames (abusive orinsulting messages)

Be brief and polite Watch spelling/grammar

Avoid spam (unsolicitedmessages to many)

Avoid sarcastic, offensivelanguage or humor

Use emoticans to expressemotion :\ :o

2nd lecture final internet

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