Anime conventions or cons are the anime equivalent of sf or gaming conventions. They may include outlandish people in outlandish and frighteningly accurate costumes--anime hair and all--at the cosplay, an art show, a dance, panels, Anime Jeopardy, LARPing, and so on, but most especially, a freaking huge dealers' room full of imported goodies and other nifty stuff, such as stuffed Mokonas and cabbits. In my experience, anime cons have a more widely mixed group of attendees in terms of gender, ethnicity, and background, not that this precludes a lot of hard-core otaku. Lots of fun, though, generally, as long as the goth-y LARPers keep to themselves...(and that certain kind of otaku that doesn't have any rudimentary personality outside of anime fandom doesn't follow me.)