What makes this so powerful is that these files can contain graphics, or snippets of animation or music, and they can contain information that you normally would have to find with special programs like ftp or gopher (which is fine for nerds, but is a real pain otherwise).
There. Now on to things that are more interesting, like ...
Netscape and Mosaic allow you to view World Wide Web files. They provide the pretty little window with all the neat buttons. Other competitors that do the same thing (basically) are things like tkWWW or LYNX (which is pure text, and hence not much fun unless you're stuck dialing in over a phone line and hence can't get graphics anyway). Netscape and its kin are clients (which is just a type of computer program). They're like different types of TV sets that show you what's being broadcast. (Not a great analogy, but there you have it). To extend the TV set analogy just a bit, some clients allow certain features that others don't. For example, in the same way that some TVs have stereo sound and others don't, Netscape allows a page to display more than one line of text next to a picture (in addition to other things), something that most other clients don't allow. By the way, things like Mosaic and Netscape are also called browsers.
If Mosaic and Netscape are like types of TV set, at the other end is the broadcasting station, the server. The server basically lets other people (all the people out there with their clients) look at a set of files --- sort of like how a broadcasting station lets viewers see TV programs. There are different types of servers, ranging from Plexus (written in a language called Perl), to NCSA's HTTPD (a C-based program), to Apache, to commercial servers like Netsite.
Now, the actual files, called pages (or TV programs, if you will), sit around on a machine that the server knows how to get to (like videotapes of a TV show sitting around inside VCRs), waiting for someone to come look at them (maybe something like the video-watching system you find in some hotels). And if you happen to own a file (the videocasette), you can always rewrite it if you want to. Your primary personal page is often called a home page, and corporations and schools often have their own home pages as well.
So, just to go over this again, you have a web server (broadcasting station) that sends home pages (TV shows) over to your client (TV set). There! Not so bad so far, eh?
To clarify matters some more, our server provides some useful services like a listing of MIT-related home pages, as well as finger and discuss gateways (a gateway is a thing that allows other programs to talk to a web server). However, people's home pages are not part of our server. Our server merely provides a direct link to other people's home pages, which live on different machines around campus.
Let's assume you are username 'foobar'. Click on the "Open" button (if you're using the client Mosaic), and type in the pop-up window:
http://www.mit.edu:8001/afs/athena/user/f/o/foobar/www/home.htmlThe above string of stuff is called a URL. Notice that the "www.mit.edu:8001" part is the name of our server (and the 8001 is the port number, but if you don't know what that means, don't worry about it). The rest is your AFS path. (For more about AFS and stuff like that, check out our informative SIPB Documents).
Yes, you can link in yet more pages to your homepage. And while that is getting beyond the scope of this simple intro, you should look at the HTML language primer for more information. There are many other great places to learn more about how to write home pages, but one really good way is to look at the actual "code" used in your favorite pages. An easy way to do this from Mosaic is to type "d" somewhere on the page you're looking at. This will pop up a box with the actual HTML code. (If you use Netscape, go under the menu "View" and select "Source".) Try it now, if you like.
Now, unfortunately, you generally can't do neat things that require someone to type stuff into your homepage without your own server ... and that's way way beyond the scope of this document! But there is lots of stuff out there on setting up your own web server (remember, though, that you will need your very own machine on the Internet to do this). For some pointers, try the WWW FAQ (Frequently Asked Questions), an excellent set of links to many places!!
There! That was a quick intro to the web. If you have any questions, feel free to email the MIT webmasters (webmaster@mit.edu), or use our comment gateway.