Quite a lot. Punk as a philosophy centers around rejection. Rejection of capitalism, socialism, politics, economics, aesthetics, logic and rhetoric. In its nature it brings this philosophy to the attention of others by being invasive, brash, vulgar and overstated. In short it attempted to "shock" people into acknowledging their values, or rather their lack of values. For example the use of the swastika was used to shock the generation who had fought against naziism, informing them that their struggles and sacrifices had ultimately been fruitless as society was still flawed at its core. Initially punk was associated with anarchism (NOT anarchy), and was quite left wing. It interpreted the legal system as part of the state apparatus by which the working classes were subjugated and oppressed. During the 80's however, it became associated with the far right, neo-Nazis, especially the anti-immigration platform in the UK and the skinhead movement in the US, where "Oy!" punk became almost synomymous with racism. This was in spite of the fact that most major punk bands, The Clash and The Jam for example, were very left-wing and sympathetic to the labour movement. They did mostly have to make little of their usually middle-class roots. Musically punk was both shocking and a rejection of the Shelleyan ideal of the artist as a genius, which had become common during the 70's as most bands contained at least one virtuoso and prog became popular. Expression was about emotion rather than skill and clarity and energetic play rather than actual musical talent became admired. Punk also largely ignored the mainstream record labels and released records independently or on small labels. Emo on the other hand is possibly an example of the first fashion trend to have been designed by corporate media. Major record labels profited from punk, but not as much as they felt they could have, and grunge caught them completely off guard (except Geffen), so they decided to create a new genre they could control from the off. It embraces much of punk and grunge anti-corporate sentiment, but has a largely peacful image, so that parents won't object. Musically it's not really a genre. Emo bands are bands that "look" emo rather than "sound" emo, though lyrical themes are common. It is aimed squarely at middle class teenagers, the easiest base to target, but the one that no record company can afford to misjudge (as they did during grunge). In terms of philosophy, Emo is utopian and oomphalic (yes that is a word, derived from the Greek world for "navel"). It seeks to create a community of like minded people who understand each other, as opposed to school, family and authority figure from whom Emo's feel disengaged. These communities are entirely accepting of kindred spirits and dismissive of, though not aggressive towards other groups. In short it's a perfectly acceptabel form of rebellion that parents will accept, even endorse, but which will make corporations millions, and also create an audience for acts that may not find one naturally (because they tend not to be very good). In terms of fashion, it combines the more benign aspects of goth, punk and skater. It short, it's a fabricated movement. Hope that explains a few things.