What is the difference between Heterosexism and Sexism?

Heterosexism and sexism sound like similar terms, but are in fact quite different.

While heterosexism is the belief of heterosexuality as the only acceptable sexual orientation, sexism, on the other hand, is based more in gender-role bias and gender stereotypes. Specifically, sexism is the assumed superiority of men over women.

In fact, heterosexism and homophobia can be used as a weapon of sexism. This is called "lesbian-baiting" and is a way to make women "fall into line".