I guess a slut is basically a woman/girl who does things for sexual excitement which are not tollerated in the social environment she lives in, while men are often allowed to do whatever they like.
I wouldn't call myself a slut even though I think I have every right for every experience that doesn't offend the rights of others.
But I like to be called "slut" by men if it means that they accept me as someone to fulfill there dirtiest fantasies.