Emo is a person usually under 20 years old. They intentionally cut or hurt them selves to relieve emotional pain, and bring it onto their wrists or other body parts. They do this because there are probably big problems in their life; a loved one died/ left, bullying, family issues ect. Most emos do not tell you they are, or make it obvious. Therefor if they do they are probably saying it for attention.
The emo look; skinny jeans, tight sweaters, band shirts, converse shoes, side swept hair covering an eye, eyeliner, perhaps numerous peircings.
Music; soft rock or punk, screamo