There are times when you might want to have some
dynamic information (information that is not constant) in your HTML
documents. This could include simple information such as the date
and time, or a counter that displays "You are visitor number xxx",
but it could also include such things as pie charts/graphs based
on user input, results from searching a database, or animations.
And the only way you can produce results like these is with CGI
scripts (though you can also do so with client-side applications
like Java and JavaScript, but that's a totally different story!).
Simply put, a script is a program! OK, OK, there
are semantic differences between the two words. If you really want
to know, pick up a book on computer programming (or is that computer
scripting :-)
You can create a lot of magic by writing a CGI program/script.
You can create graphics on the fly, access databases and return
results, and connect to other Internet information servers.
The answer is located in the first three lines of
the Perl manpage:
Perl is an interpreted language optimized for
scanning arbitrary text files, extracting information from those
text files, and printing reports based on that information.
Most CGI applications involve manipulating data in some fashion
and accessing external programs and applications. Perl provides
easy-to-use tools that make these tasks a cinch.