This is an extremely basic Perl question. Not that I mind occasionally helping somebody out if there's some aspect of Perl they're having problems with, but quite frankly, if you're wanting to learn the basics, I'd suggest you find an online tutorial or buy a book such as Learning Perl or Programming Perl. Examining existing Perl code can also help if you learn by example.

In addition, read some of the stock Perl documentation (as well as the perlfaq and the Perl Monks FAQ).

I do wish you luck, though.