A punk rocker is some one who likes to listen to punk rock. They hate authority and the government or just want to change it. The music often talks about that type of thing. Most people think you have to dress a certain way to be punk, but there really is no set style except punk rockers tend to look very rebellious because they are non conformists. The life style is to be your self and not care what any one else thinks about it.
Punk rockers listen to music like The Ramones, Pennywise, Rise Against, NOFX, Bad Religion, The Sex Pistols, Anti-Flag, and The Casualties. They don't listen to fake punk like Good Charlotte, Simple Plan, or Avril Lavigne.