Network, Internet Network, Internet and World Wide Web and World Wide Web Essential Concepts Essential Concepts Natalia Mosina - 2005 Natalia Mosina - 2005
Network, Internet and Network, Internet and World Wide WebWorld Wide Web
Essential Concepts Essential Concepts
Natalia Mosina - 2005 Natalia Mosina - 2005
NetworkNetwork
• Most people work in a network environment
A network is a collection of computers connected together with special hardware and software to manage it.
LAN – local area network (small area)
WAN – wide area network (long distances)
From LAN to WAN
(a) Home Network
(b) Local Area Network
From LAN to WAN (continued)
(c) Wide Area Network
The InternetThe Internet
A network of networks,A network of networks,
interconnected collection of interconnected collection of networksnetworks
Began in 1960s as Began in 1960s as government (military) project government (military) project
It is a hardware!It is a hardware!
Consists of computers Consists of computers and the communications and the communications links that connect themlinks that connect them
The World Wide WebThe World Wide Web
Began in 1991 at the European Particle Began in 1991 at the European Particle Physics Laboratory (CERN) in Switzerland Physics Laboratory (CERN) in Switzerland
It is a software!It is a software! Consists of different files, documents, and Consists of different files, documents, and
software that stores and retrieves those software that stores and retrieves those files.files.
Web is a collection of files that reside on Web is a collection of files that reside on Web Servers that are located all over the Web Servers that are located all over the world.world.
Client vs. ServerClient vs. Server
When you connect to Internet to become When you connect to Internet to become part of the web, your computer becomes a part of the web, your computer becomes a Web client in a worldwide client/server Web client in a worldwide client/server network.network.
Web browser is the software that you run Web browser is the software that you run on your computer to make it work as a on your computer to make it work as a Web client.Web client.
A Client/Server ModelA Client/Server Model
A A serverserver (Web server or Web site) is any (Web server or Web site) is any computer that stores documents and furnishes computer that stores documents and furnishes them upon request them upon request
AA client client is any computer that requests services is any computer that requests services (requests and then displays documents )(requests and then displays documents )
Every client must be able to display every Every client must be able to display every document from every server and does so document from every server and does so through a browser (e.g., Netscape or Internet through a browser (e.g., Netscape or Internet Explorer) Explorer)
Acronyms Acronyms
HTTPHTTP – HyperText Transfer Protocol is – HyperText Transfer Protocol is used to transmit Web documents used to transmit Web documents
HTMLHTML – HyperText Markup Language is – HyperText Markup Language is the language for all Web documents the language for all Web documents
ISISP P – Internet service provider – Internet service provider IP - IP - Internet protocolInternet protocol TCPTCP - Transmission Control protocol - Transmission Control protocol DNSDNS – Domain Name System – Domain Name System
Connecting to the InternetConnecting to the Internet
At Work or School At Work or School Via a Local Area Network Via a Local Area Network
At Home At Home Traditional Modem (56Kbps) Traditional Modem (56Kbps) Cable Modem Cable Modem
Uses TV cable Uses TV cable Requires network card Requires network card
DSL Modem DSL Modem Voice and data on the same line Voice and data on the same line Requires network card Requires network card
Uniform Resource Locator (URL)Uniform Resource Locator (URL)
http://www.prenhall.com/reed/index.htmlhttp://www.prenhall.com/reed/index.html
Protocol (means of access)
Web Server
Directory where the Page is stored
Name of the page Or document
URL URL
Top-level domains include “edu,” “gov,” and Top-level domains include “edu,” “gov,” and “org,” but “com” is most common “org,” but “com” is most common
Examples: Examples: www.microsoft.comwww.microsoft.com www.nba.comwww.nba.com www.whitehouse.govwww.whitehouse.gov www.miami.eduwww.miami.edu
E-Mail (Electronic Mail)E-Mail (Electronic Mail)
E-mail is simply a means of sending E-mail is simply a means of sending messages via computer messages via computer
Business is using more e-mail and fax Business is using more e-mail and fax To access, you must have a mail server To access, you must have a mail server
and/or software and/or software Each person has a username and pass-word Each person has a username and pass-word All mail programs allow you to Send, All mail programs allow you to Send,
Compose, Reply, and Forward Compose, Reply, and Forward
An E-mail AddressAn E-mail Address
Every e-mail address is unique and consists Every e-mail address is unique and consists of two parts, a user name and a host of two parts, a user name and a host computer: computer: [email protected]@anyschool.edu
The@ sign is required The@ sign is required The host computer can be omitted if you are The host computer can be omitted if you are
logged onto the same network or host logged onto the same network or host computer computer