What is the WebWWW or the Web is the largest information service on the Internet. It was invented at CERN by Tim Berners-Lee, and developed here from 1990 to 1994.
The cables (Appletalk, Ethernet, telephone) are like the road system. Roads are different, but all interconnected.
The Internet is like the traffic rules: on an interconnected busy road system, we all agree to drive on the right hand side, to stop at red lights, etc. For any two computers on the Internet, there is not only a road between them, they also have agreed to talk to each other using the same rules (protocol).
WWW is like a parcel delivery service: you use the cables and the Internet protocol to order documents from remote servers. This is very similar to mailing an envelope with an order to a company, which then ships the goods back to you.
How does it Work ?
WWW is a client-server system with both clients and servers spread all over the world. Your machine has a client or browser which displays a page of information with sensitive text parts in it:
You can now look at the document as long as you like, there is no traffic going on. It is like if you ordered a book by post and have received it.
- you click on a sensitive text part.
- your computer opens a connection to another computer: a server.
- your computer asks the server for a document by sending it a request.
- your computer then waits for the reply.
- the server computer receives the request and looks up the document.
- the server sends the document back to your computer.
- your computer receives the document and closes the connection with the server.
- your computer displays the document on your screen.
Internet connection and Browsers Your computer at CERN is connected to the Internet because it can talk the Internet protocol TCP/IP.
Your computer also has a World-Wide Web browser, which may be one of these:
The browser is often called "the client software". Furthermore Web browsers and Web browsing at CERN help pages will guide you to smoothly navigate among billions of documents.
ServersThe documents are on server computers. The CERN Welcome page is stored on a server in the computer centre as most of the documents that you need for work at CERN.
WWW is Platform independent:
- It does not matter whether you have a Macintosh, a PC compatible or a Unix workstation.
- It does not matter whether the documents are stored on a Macintosh, an PC or a Unix server.
WWW is Format independent
- HTML is not a format but a way of structuring documents.
- Formatted documents are available through their own applications (helper applications).