In fan fiction, what do the terms "Slash" and "Yaoi" mean? Now I THINK I know what they mean, but I'm not certain, so I need some nerds more depraved than myself to clear this up for me.

As far as I know, it's something along these lines:

The term Slash comes from the slash between two names, like Kirk/Spock. A Slash story refers to a story of a romantic encounter between two characters.

Yaoi refers to manga/anime which depicts boys having sex with each other as the focus of the narrative.

BUT I'm not exactly an expert in this field, so others may correct me.