Review of Basic Internet Concepts
To provide information on basic Internet terms and concepts
The Internet is a network of computer networks. It makes it possible for any computer connected to it to send and receive data from any other computer connected to it.
America Online, Comcast, Earthlink, etc. are examples of Internet service providers. They make it physically possible for you to send and access data from the Internet. They allow you to send and receive data to and from their computers or routers which are connected to the Internet.
World Wide Web is an example of an information protocol/service that can be used to send and receive information over the Internet. It supports:
- Multimedia Information (text, movies, pictures, sound, programs . . . ).
- HyperText Information (information that contains links to other information resources).
- Graphic User Interface (so users can point and click to request information instead of typing in text commands).
The World Wide Web is an example of an information protocol/service that works using a Client/Server software design. (Client/Server is an ADJECTIVE that describes the software, not a noun!) A service that uses Client/Server design requires two pieces of software to work: Client software which you use to request information, and Server software which an Information Provider (like Fermilab or a museum) uses to answer requests and provide their information. Most Internet information protocol/services are designed this way.
The Client/Server relationship is similar to the relationship between the TV in your house and the TV stations you can select. Your TV acts as a client by tuning in (requesting information) from a TV station which acts as a server by broadcasting (serving) the information.
This means that if you encounter an error while using your Web browser, this may be due to a problem with the Web server you are contacting for information. It does not necessarily mean that your browser isn't working, or that you installed something improperly. Just like in the case of the TV and the TV station, sometimes problems are due to a bad TV, and other times they are caused by a problem at the TV station.
The server software for the World Wide Web is called an HTTP server (or informally a Web server). Examples are Apache and IIS. The client software for World Wide Web is called a Web browser. Examples are: Netscape, Internet Explorer, Safari, Firefox, and Mozilla. These examples are particular "brands" of software that have a similar function, just like Lotus 123 and Excel are both spreadsheet software packages.
There are many different information protocols/services besides HTTP (HyperText Transfer Protocol).
Some of these are:
- E-mail (SMTP) - for sending electronic mail messages.
- Usenet News (NNTP) - for having electronic group discussions.
- File Transfer Protocol (FTP) - for transferring files between computers.
- Telnet - for running programs on remote computers.
- Various Others . . .
Each of these works in a client/server manner by having a "language" defined that allows the client and server to communicate with each other in order to give users the information they request. These different languages have different purposes, capabilities, and advantages.
One of the nicest things about the World Wide Web is that it provides "one-stop shopping" for getting information over the Internet. In the past, you would have needed to learn how to use many different software applications in order to use all these services. Now you can use E-mail, News, FTP, Telnet, WAIS, Gopher, and HTTP services all through your favorite Web browser.