Tech Talk: Anatomy of a Web Address
by Paula Eisenberg
(September 15, 2002) They are everywhere now, on every
kind of print, television, radio and even sky-writing
ad. You can't get through the day without seeing URLs,
those strings of symbols, letters and numbers pointing
the way to websites. But what do they really mean? Why
all the arcane slashes and dots and acronyms?
First of all, what does URL stand for, anyway?
URL=Uniform Resource Locator, which
is a fancy name for "path to a file on the Internet."
Think about it this way: in order to deliver a letter
to you, the Post Office must know your street address.
Your postal "URL" is 146 Main Street, Anytown,
NY 10538. There might be a 146 Main Street in another
town, so the envelope needs to have the full address
(path) in order to reach you.
Let's break down the URL of the page you're reading
now, http://www.larchmontgazette.com/2003/features/techtalk/20020915abouturl.html:
- http, or HyperText Transport
Protocol, which just means the file you're
trying to reach is sitting on a server that handles
hypertext documents, and "protocol" tells
your browser which kind of file you're looking for.
Hypertext is the heart of the Internet, the method
by which "links" are made. You got here
by clicking on a hyperlink on another webpage. More
about that in another article. The http is always
followed by two forward slashes and a colon, as in
//:
- www., or World Wide Web. The Web
is relatively new as a part of the larger Internet.
It's been around only since about 1995, believe it
or not. Before that, the Internet was mostly black
and white, no graphics, no music, no video. It was
a way for people in the computer, engineering and
military communities to send text files to each other.
Then along came Tim Berners-Lee, the man who invented
hypertext, and the Web was born. The period after
www just separates that part from the next part of
the URL.
- larchmontgazette.com/ is the host
computer and domain name. When we started the Gazette,
we had to register the domain name so nobody else
could use it on the Internet, and then we had to find
a host for the site. The hosting company is in another
state, and it owns the heavy-duty computers (servers)
where our files sit. Those files are "served"
to you when you click on hypertext links to get here,
and when you navigate around within our site. To get
the files to the host computer in the first place,
we send them via yet another protocol called FTP,
or File Transfer Protocol. Sounds complicated, right?
We use specialized software to create the pages and
send them over the Net to the host server, where they
wait for you to discover them. The last part of the
domain name, the .com, means our site is commercial,
rather than .gov (governmental) or .edu (educational)
or .org (originally reserved for non-profit organizations)
or .net (originally reserved for Internet service
providers).
- features/techtalk/ are folders
on the larchmontgazette.com server. Features is the
large section where we keep all of our feature stories,
and /techtalk is a sub-folder inside
/features. The file system on your
own computer is organized this way. Your old-fashioned
manila file folders in your desk are probably organized
this way too!
- 20020915abouturl.html is the actual
filename of this page. To help us organize our files,
we name the file with the numerical date on which
we wrote the article first, (I am writing this one
on Sept. 15, 2002). Then comes the descriptive name
of the file, abouturl. Last is the type of file it
is, in this case html, for HyperText
Markup Language. HTML is the code which lets your
browser display this page to you. Want to see the
code? Up on your top menu bar, click on View/Source
(Microsoft Internet Explorer browser) or View/Page
Source (Netscape Navigator browser). You'll see all
the strange markings surrounding plain English. That's
HTML code, and it isn't as hard to understand as it
looks. Other types of files you'll see on the Web
are .jpg and .gif, which are image files, and .avi
and .mpg, for video and music.
Luckily, you seldom need to type an entire URL into
the address bar of your browser. All you need to do,
usually, is click on a hyperlink from another webpage.
Sometimes you can guess about a URL. Let's say you want
to visit the CNN website. You could take a guess that
it's http://www.cnn.com, and you'd be right. You can
even shorten that and just type www.cnn.com, or even
cnn.com, and you'd still get there. Many sites now allow
you to reach them without typing the .www.
part of the URL.
If you have questions about this or anything else related
to computers, technology or the Internet, send
me an email and I'll do my best to help you.
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