WWW

I wish I had six weeks just to talk about the World Wide Web (a.k.a. WWW or "the Web."). If you think Gopher is neat, wait until you start playing around on the Web :)

Unfortunately, I don't have six weeks to talk about the Web -- I only have two lessons. Because of this, we are going to go through the Web like Sherman went through Georgia (1).

That's the bad news. The good news is that there are a lot of REALLY good Web guides available, and I am even seriously considering developing my own Web workshop that I will offer late next year (2).

Until that time comes, however, let's talk about the BASICS of the Web.

In the last few lessons I showed you how most Gopher menus are linked together. We started out in the gopher.squirrel.com root menu, and eventually ended up at the SURAnet gopher menu. We were able to do this because the menus that we traveled through had links to menus and files that were located at other Gopher sites.

Because Gopher menus are linked together, a whole world of information is available to us with just a few keystrokes!

Imagine if we were able to take these links one step further. Instead of linking menus, we could link documents together. You could read one document, find a keyword in that document that really interests you, touch that keyword, and automatically be taken to a NEW document somewhere else in the world -- and this new document could even have links to OTHER documents around the world, and so on.

Sound too good to be true? It isn't, thanks to something called "hypertext." If you have ever played with Apple's HyperCard program or the "help" menus in the latest Microsoft packages, you have already experienced hypertext. You "select" a highlighted word -- usually by clicking on it with a mouse -- and you are taken into an entirely new document or help screen.

The World Wide Web is based on hypertext. It is possible for you to go roaming around the Web, bouncing from document to document, using nothing but the links in those documents!

Just as you can access Gopherspace through a Gopher server or client, you can access the Web through something called a "browser." A browser can read documents, fetch documents, access files by FTP, read Usenet newsgroups, telnet into remote sites, and even travel around Gopherspace. In short, everything that we have talked about from MAP08: Usenet to MAP22:Gophermail can be done using nothing but a Web browser!

The Web is able to accomplish all of this thanks to something called URLs ("earls") -- Universal Resource Locators. URLs list the exact location of any Internet resource.

If you think about it, giving every Internet resource a unique address is the hard part. Once you have given something an address, linking to it is pretty easy :)

What is really special about the Web is that the Web does all of this "behind the scenes." It is possible for you to bounce from one link to another without ever knowing the exact address of where you are, or even how you got there.

If you ever want to jump directly to a particular Internet resource, however, you are going to need to know a little bit more about URLs. Here are a few basic URLs:

     file://wuarchive.wustl.edu/mirrors/msdos/graphics/gifkit.zip
ftp://wuarchive.wustl.edu/mirrors
http://info.cern.ch:80/default.html
news:alt.hypertext
telnet://dra.com
Gee ... those look a little like FTP addresses, don't they?

The first part of an URL -- the stuff before the colon -- tells the browser how to access that particular file. For example, to access

    ftp://wuarchive.wustl.edu/mirrors
your browser would use FTP.

Most of the access methods are pretty straight-forward. Here is a list of some of the more common access methods that you are going to see listed in the first part of URLs:

          method        what it stands for
------ ---------------------------------------

ftp File Transfer Protocol
file File Transfer Protocol (same as ftp)
news Internet News Protocol (Usenet)
gopher Gopher
telnet Telnet
http Hypertext Transport Protocol
We've used all of these before, except for "http". If you ever see a URL with "http" at the beginning of it, that means that the file is a hypertext document (with hypertext links to other documents).

The rest of a URL -- the stuff after the colon -- is the address of that particular file. In general, two slashes (//) after the colon indicates a machine name or address.

For example,

    file://wuarchive.wustl.edu/mirrors/msdos/graphics/gifkit.zip
is the URL for an FTP file at wuarchive.wustl.edu, and
    http://info.cern.ch:80/default.html
is the URL for a hypertext document at info.cern.ch, port 80.

Posted bySumedh at 11:50 PM  

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