Scholarships and fellowships are almost the same thing. It's usually free money to your education. Some may require work, before you get paid though. Scholarships is not only based on GPA, but what extra activities you did and volunteer work. If you win a huge fellowship like a NSF you practically got most of your graduate school paid for along with being accepted to the college of your choice.
It has nothing to do with fraternities. Plus, I really believe it depends in the college how clubs usually behave. My university is a really quiet place since I live in the central valley so no real big parties there.
