The first part of the URL specifies the protocol, or method of access by which the resource will be obtained. It is the name of the protocol followed by a colon and two forward slashes. This is where the http:// comes from. "http", or HyperText Transfer Protocol, is the protocol by which you obtain web pages. The other common protocols that are used are "ftp" and "gopher." FTP is used to transfer files between computers over the Internet. Gopher is a text-based information retrieval system similiar to the World Wide Web. Most web browsers can handle retrieving information using any of these protocols.
The second part of the URL specifies the host on which the resource is located followed by a slash. Examples of such things are www.radionet.com, www.phoneboy.com, and www.webdzine.com. Most web sites have a 'www' in their host name, which reenforces the idea that you are accessing a web site, though not all web sites have a www in their hostname.
The third part of the URL is optional. It specifies where exactly on the web site a particular resource is located. Usually this part of the URL is left out if you're just referencing a web site (for instance, http colon forward slash, forward slash, www.radionet.com). In this case, a "default" page will be displayed. But if you're accessing a specific document directly, for instance, my staff page on the RadioNet Talk Radio Home Page, you need the "full URL" for that page (http colon forward slash, forward slash, www dot radionet dot com slash dameon.html (http://www.radionet.com/dameon.html)).
A fourth part of the URL that you might see a "query string", which starts with a question mark and then a bunch of gobbledygook. The gobbledygook are "parameters" that are passed to a particular document or program that is being referenced by the other three parts of the URL. You see this most often when you use a search engine or any other website that has to access a database for information. You will rarely give a URL with this information to another person, though you might bookmark it for one reason or another.
URLs are a great way for keeping track of stuff you've run across on
the net and want to reference later. Web browsers allow you to keep track
of these URLs in what are called hotlists or bookmarks. In fact, the now
infamous search engine Yahoo was originally just a listing of bookmarks
that grew and grew as the World Wide Web gained
popularity.
Suppose you want to "verbally" communicate the URL of a cool web page
to someone. Earlier I mentioned a URL complete with http colon forward
slash, forward slash. Normally, I wouldn't do it this way. Why? Almost
all URLs for web pages begin with http colon forward slash,
forward slash (http://). It's very hard to say that. I'm not the only one
who thinks this. Columnist David Plotnikoff of the San Jose Mercury News
wrote on April 28, 1995:
He went on to ask his readers how to shorten http:// in casual conversation. While he got several amusing responses, his "final say" was to call it "all the usual junk."
What's really happenins is that the really clunky part of this, the http://, is usually *dropped*. Even on shows about the Internet like RadioNet Talk Radio, they usually don't say the ubiquitus http:// when we're referencing a web page, including RadioNet Talk Radio.
And if you think about it, the http:// is really redundant. Especially
when you consider most web sites have 'www' somewhere in the name and only
allow access to their materials via the HyperText Transfer Protocol. Netscape
Navagator, the most popular browser on the Internet, does not make you
enter in the http:// when you reference a
web site. It assumes it's there if it's not already.
So the next time you hear someone say "www.whatever.com", hopefully you'll remember they're talking about a web site. And hopefully you'll remember to put the http:// in front of it if you're not using Netscape. ;-)