"So far, we've talked about Perl as a language for mangling
numbers, strings, and files - the original purpose of the language.
Now it's time to talk about what Perl does on the Web. In this
installment, we're going to talk about CGI programming."
"The Web is based on a client-server model: your browser (the
client) making requests to a Web server. Most of these are simple
requests for documents or images, which the server delivers to the
browser for display."
"Of course, sometimes you want the server to do more than just
dump the contents of a file. You'd like to do something with a
server-side program - whether that "something" is using Web-based
e-mail, looking up a phone number in a database or ordering a copy
of Evil Geniuses in a Nutshell for your favorite techie. This means
the browser must be able to send information (an e-mail address, a
name to look up, shipping information for a book) to the server,
and the server must be able to use that information and return the
results to the user."