in reply to What Makefiles do
Just to add to everyone else's comments: You probably have "make" and "compile" joined in your mind, and that's not unreasonable given make's history.
But if you look at make's documentation, you'll find that it can run virtually any command that you can on the command line, which makes it extremely useful when, for example, you want to create a package to load up to CPAN. You could use it to do something as trivial as display the current time, or you could use it to create graphics packages. The commands in the makefile are up to you.
By the way, having said that, check out Module::Build, which makes some of the Makefile configuring much easier.
Edit: Added missing "have" to the text. Sorry about that.