It's not people who cut themselves, or hate themselves and life. Not people who dress in skinny jeans with hair over their eye and band tee's. Emo came from emotive music and people began saying things like they cut themselves or all they do is cry, when that style became popular. Emo is really just a style of music that has meaning to it. Instead of things like 'Can't Be Tamed by Miley Cyrus' that has no depth, there is songs like 'Miserable At Best by Mayday Parade' that has depth. Basically, emo came about to label people who have a sensitive side.
Typical stereo type.
Person #1- That guy is wearing skinny jeans and isn't smiling, he must be emo.
Person #2- Yeah. He probably cuts himself every night.
*Person 1 and 2 start laughing*