WHAT IS WAN

What is WAN?

A wan is a data communications network taht covers a relatively broad geopraphic area and that often uses transmission facilities provided by common carriers, such as telephone companies.wan technologies generally function at the lower three layers of the osi reference model: the physical layer,teh data link layer,adn the network layer.

WAN DEVICES

WAN use numerous types of devices that are specific to wan environments.wan switches,access servers,modems,csu/dsus,and isdn terminal adapters are duscussed in the following sections.other devices found in wan environments that are used in wan implementations include routers,atm switches and multiplexers.

Modem

A modem is a device that  interprets digital and analog signals,enabling data to be transmitted over voice-grade telephone lines.at the source, digital signals are converted to a form suitable for transmission over analog communicaiton facilities.at the destination,these analog signals are returned to their digital form.

Read More

WHAT IS LAN

What is LAN?

A lan is a high-speed data network that covers arelatively small geographic area.it typically connects workstations,personal computer,printers,servers,and other devices.lans offer computer users many advantages, including shared access to devices and applications,file exchange between connected users,and communication between users via electronic mail and other applications.

Lan devices.

Devices commonly used in lans include repeaters, hubs, LAN extenders, bridges, LAN switches, and routers.

Read More

WHAT IS HTML

What is HTML ?

·                     HTML (hyper text markup language) is the code that is used to produce web pages.

·                     By using frontpage you do not need ot learn HTML, but a knowledge of HTML basics is very useful should you want ot manually modify some of the code behind your web pages

You can create HTML using a text editor or word-processor and enter all teh data and codes     directly,but these days most prople will use a web page creation   program,such as Microsoft's Front page.

When you view a page, coded using HTML, in a web browser program (such as Microsoft Internet Explorer), the browser strips out the HTML code and you see the effect of that code, rather than the code itself !

Read More

WHAT IS INTERNET & HOMEPAGE

What is the internet?

What is an internet browser?

You use an internet browser program, such as microsoft's internet explorer or netscape's navigator (or  communicator) to view material on the www. You can go to a web site and teh information on teh site can be displayed by the browser program.

What is an internet server?

An internet server is a computer that is permanently attached to the rest of hte internet , and which publishes information that can be viewed by other people using their internet browser programs.

What are urls?

Hte uniform resource locator (url) is teh internet address that internet browsers ue to find your webpages. You also use urls when you create links from one part of your web sete to another.

What is a web site?

A web site is a group of web pages.a web page is simply a document composed in html tha tcan be access on the web.a web page is not the same size as a piece of paper,it can be any size you wish.it is good practice however to keep the physical size and file size and file size of your web pages as small as possible, as large pages will take longer ot load.

What is a web site homepage?

Hte home page is teh starting page for your web site. Ideally when people visit your web site they will see your home page first and then follow links that you have pre-defined to other pages within your web site,or indeed to other web sites.

You should always call your home page file inded.htm(or index.html),rather than home html or first.html. There are good technical reasons for this !

What is an internet search engine?

An internet search engine is a program that allows you to enter words or phrases and search the web for sites containing relecant information. There are many examples, such as lycos, infoseek, and yahoo.

Read More

Open system interconnection reference model

Open system interconnection reference model

The open system interconnection (OSI) reference model describes how information from a software application in one computer moves through a network medium to a software application in another computer.the osi reference model is a conceptual model composed of seven layers,each specifying particular network functions.the model was developed by the interneational organization fo rstandardization (ISO) in 1984, and it is now considered they primary architectural model for intercomputer communications. Tha osi model divides the tasks involved with moving information between networked computers into even smaller, more manageable task groups.a task or group of tasks is then assigned to each of the seven osi layers.each layer is resonably self contained so that the tasks assigned to each layer can be implemented independently.this enables the solutions offered by one layer to be updated without adversely affecting the other layers.the following list details the seven layers of open system interconnecion (OSI) reference model:

·                     Layer7_____________Application

·                     Layer6_____________Presentation

·                     Layer5_____________Session

·                     Layer4_____________Transport

·                     Layer3_____________Network

·                     Layer2_____________Data Link

·                     Layer1_____________Physical

Read More

What is the world wide web and what makes it work?

What is the world wide web and what makes it work?

The www incorporates all of the internet services abouve and much more.you can retrieve documents,view images,animation,and video,listen ot sound files,speak and hear vouce,and view programs that run on practically any software to do these things.when you log onto the internet using netscape or microsoft's internet explorer or some other browser,you are viewing documents on the world wide web.the current foundation on which the www functions is the programming language called html.it is html and other programming imbedded within html that make possible hypertext. Hypertext is teh ability to have web pages containing liks,which are areas in a page or buttons or graphics on which you can click your mouse button to retrieve another documet into your  computer.this "clickability" using hypertext links is teh feature which is unique and revolutionary about the web.

Read More

What is Internet

What is the internet?

Tha internet is a network of networks, linking computers to computers sharing the tcp/ip protocol.each runs software to provide or "serve" infromation and /or to access and view information.the internet is the transport vehicle of r the information stored in files or documents on another computer.it can be compared to and international communications utility servicing computers.it is sometimes compared ot a giant international plumbing system.the internet itself does not contain information.it is a slight misstatement to say a "document was found on the internet." it would be more correct to say it was found through or using the internet.what it was found in (or on) is one of the computers liked to the internet.

computer on the internet may use one or all of the following intenet services.

·                     electronic mail(e-mail).permits you to send and receive mail.provides access to discussion groups.

·                     telnet or remote login.permits your computer to log onto another computer and use it as if you were there.

·                     FTP or file Transfer protocol. allows your computer to rapidly retrieve complex files intactfrom a remote computer and view or save them on your computer.

·                     Gopher. an early,text-only method for accessing internet documents.Gopher has been almost entirely subsumed in the world wide web, but you may still find gopher documents linked to in web pages.

·                     the world wide web (WWW or "the web"). the largest, fastest growing actibity on the internet.

Read More