Roadmap96: MAP23 - WWW | WebReference

Roadmap96: MAP23 - WWW

Roadmap96

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MAP23: WWW

"Ah! the clock is always slow; it is later than you think."
-- Robert W. Service, It Is Later Than You Think

I wish I had six weeks just to talk about the World Wide Web (a.k.a. "WWW" or just "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 have only enough time to write 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. I am even writing my own Web training workshop (called "Atlas") that will debut in the Fall of 1996 (2). Until Atlas comes, however, let's talk about the BASICS of the Web.

In the past couple of lessons, I have shown you how most Gopher menus are linked. For example, we started out in the "gopher.squirrel.com" root menu and eventually ended up at the InterNIC. We were able to do this because all of the Gopher menus that we traveled through had links to menus and files that were located at other Gopher sites. Because Gopher menus are linked, 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. Suppose that, instead of linking just menus, we could link *DOCUMENTS*. 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 some of the latest Microsoft software packages, you have already experienced hypertext. In 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 "Web browser." A Web browser can read documents, fetch or download documents, access files by FTP, read Usenet newsgroups, TELNET into remote sites, and even travel around Gopherspace. In short, almost everything that we have talked about in the past 22 lessons can be done using only a Web browser!

The Web is able to accomplish all of this thanks to something called URLs (pronounced either "earls" or "you-are-ells"). URLs are "Universal (or Uniform) Resource Locators," and they list the exact location of pretty much *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://www.yahoo.com/
     news:alt.hypertext
     telnet://toybox.infomagic.com:2010

Gee ... those look a little like FTP addresses, don't they?

The first part of a 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
     news        Internet News Protocol (Usenet)
     gopher      Gopher
     telnet      TELNET          
     http        Hypertext Transfer 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) and it can be accessed only through a Web browser.

The rest of a URL -- the stuff after the colon -- is the address of that particular resource. The stuff after the two slashes (//) indicates a machine name or address (remember those from MAP11: TELNET?). For example,

     file://wuarchive.wustl.edu/mirrors/msdos/graphics/gifkit.zip

is the URL for an FTP file at "wuarchive.wustl.edu," and

     http://www.w3.org/pub/WWW/MarkUp

is the URL for a hypertext document at "www.w3.org"

 

TOMORROW:

HOMEWORK:

If you are planning on becoming a SERIOUS Web guru, I have placed the WWW FAQ on the LISTSERV file server at the University of Alabama. Alabama's LISTSERV address is LISTSERV@UA1VM.UA.EDU (that's "you-ay-won-vee-em"), and the WWW FAQ is broken into two parts:

          filename     filetype
          --------     --------                    
          WWW          FAQ1          
          WWW          FAQ2

You can use the GET command to get either or both of these files (remember, do not reply to this letter -- you MUST write a new letter to the LISTSERV file server at the University of Alabama with your GET commands).

NOTES:

(1) General William Tecumseh Sherman was the Union Army General who burned a path 100 miles wide from Atlanta to the sea during the U.S. Civil War.

(2) Kristen Burke, a friend of mine at the University, recently heard me promise that after this workshop I would *NEVER* do anything like this again. She bet me that I would change my mind. She won. :)


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Originally written by Patrick Douglas Crispen