What? Prologue?

Can anybody tell me what exactly a prologue is? What do you need it for? Do you have to have one for your novel? Thanks a lot!!

A prologue is an introduction to your novel, usually set apart from the actual plotline (Ie- the main character). It introduces the conflict, setting, world, magic, something along those lines.

They are highly discouraged.

Cram all that stuff into your novel proper, and don't bother separating it all. It's more fun discovering the conflict as you go.

*ahem
It doesn't HAVE to introduce the conflict, setting, world, magic, etc, In fact it's probably better if it DIDN'T introduce the so forth and above.
A prologue should be only about 1,000 words long, it's supposed to set up a hook, giving a reader a little taste, leaving them wanting more. (Of course the book then has to follow up)
It is NOT a beginning, it's an intro to the beginning.