What is "Greek" life in college and is it bad?

I'm actually kind of afraid of sororities and fraternities...All I ever hear is how people get inducted and how they haze people and stuff. They treat them really badly and make them do really degrading stuff, like make a girl not wear any pad or tampons while she's on her period so that it gets everywhere. You know crazy stuff like that. Is it true that "greek" life is really like this? Is it out of control party stuff?