Golf is a game in which players try to put a little ball in a little hole with the fewest attempts to do so (called "strokes").

Perl golf attempts to write a program that achieves some goal in the fewest strokes also—keystrokes. Programmers compete to write the shortest code possible to do the same thing.

Personally, I dislike Perl golf because it perpetuates the notion that Perl is a line noise write-only language.