define emo?

When i think about what bands are emo, the only band that comes to mind is Dashboard. Honestly, i know some of these "emo kids," but most of them (jet black hair, tight clothes) listen to hardcore, post punk, and the sort. Are screamo, hardcore, punk all part of that shitty label everyone denies that they are a part of? Or does emo consist of a few bands that cant seem to get away from whining about their ex'es?

Personally, i like a lot of different bands. Some may be labeled as "emo, ska, punk, whatever," but in my case, i dont listen to things just because its cool to. I hate these stupid sub-genres, its all rock and roll. Also, those poser, wanna be trendy kids, bug the hell out of me.

Donut, If im not mistaken, I have heard Bright Eyes being labled as emo.