Not a style, not the music, not attitude but a way of life. Punk is anti-establishment, and always stands up for what it believes.
No-one is more punk than anyone else, if you turn it into a punkness competition then you aren't punk, plain and fucking simple, you're just a dicktard.
Punk Bands: The Clash, The Buzzcocks, The Sex Pistols, Stiff Little Fingers, The Circle Jerks, Generation X, Iggy & the Stooges... many more. Look for it and listen.
Dicktard #1: Oh I'm so much more punk than you, I'm wearing a spiked belt!
Dicktard #2: No you're not, cos im wearing a spiked belt and I have red hair!
Real Punk: Fuck you, you stupid shits. Punk is about expression and idividuality and creativity, not being 'punker than thou'. Assholes.