Generally, scripts are only several lines of code which do some useful function that would be overkill to write in a full-featured language. With Perl, you can go either way. You can write Perl scripts and Perl programs. Larry Wall (the creator of Perl) once said "You can write Perl programs, and you can write C scripts. More people talk about Perl programs than C scripts, so I guess that means Perl is more versatile".