A common Perl-pitfall is to write cryptic code. In that context, Perl do provide for comments, albeit not very flexible. Perl treats any thing from a hash # to the end of line as a comment. Block comments are not possible. So, if you want to have a block of comments, you must ensure that each line starts with #.
Everything other than comments are Perl statements, which must end with a semicolon, like the last line above. Unlike C, you need not put a wrapping character \ for long statements. A Perl statement always ends with a semicolon.