The first one starts with the letter "p". The second one starts with the letter "w".

Maybe you want to be more explicit in what you ask. You might want to read How (Not) To Ask A Question by jeffa, and you might also want to read the Perl documentation for while and print, as found via the commands perldoc -f while and perldoc -f print.

Perl evaluates most of its statements in a left-to-right fashion, which implies that the order in which things appear is relevant.