It all started with a few bands and one little radical youth culture movement in the 1970s -- today, though, punk has proliferated everywhere, sprouting a seemingly endless number of sub-genres and -cultures, the differences between which, for most of us, are subtle at best. I can't run through every style of punk here (you could fill a book) but I want to touch on at least a few that I have known.
Unlike other types of punk, gutters are known more for their lifestyle than for adhering to one or another subgenre of punk music. Rather, they're the punks you see living on the street, aggressively bumming for change (and getting a bit snippy when denied). Dreadlocks and mohwaks are popular, as are nose rings, "sleeves" of tattoos, and accessorizing with dogs is also common. (I see a lot of cardboard signs that say things like "Need $ for beer & dog food," for instance; always a sympathy-getter!) While often described as "voluntarily" (and sometimes "militantly") unemployed, many struggle with mental illness, just like regular homeless people.
Growing up in Florida, I knew a few: strictly punk in terms of musical tastes (tending toward the hardest, fastest stuff) and hairstyle, their clothes were often a giveaway; a mohawked guy in greasy overalls? Definitely a redneck punk. (By the way, if you haven't seen my article on the origins of hairstyles, including the mohawk, check it out.) My friend Jordan was one: he worked at a pig farm during by day, sought out alcohol and mosh pits by night. (Needless to say, he a was a fragrant dude.)
I knew straight edge kids in high school, but haven't met any in years. They're anarchy-loving punks who don't drink, smoke, do drugs or have casual sex (usually), and could sometimes be identified by black x's magic markered on the backs of their hands, or a by a frequently-made x-shaped crossing-of-the-arms gesture. Some were also vegetarians or vegans -- definitely an aberration amongst the red meat-loving punks that I knew. But where have all the straight-edgers gone? Let us know if you know one, or are one!
Proving that punk rock wasn't just for (and by) boys, the Riot Grrrl! movement started in the early 90s, and is often associated with feminist protest. Probably my favorite punk band, Bikini Kill, is also one of the original Riot Grrrl! acts, and helped pave the way for bands like L7, Hole and others. Often accused of being "anti-boy" by underground media of the time -- Bikini Kill frequently provoked male moshers by insisting they move to the side and make way for women near the front, for instance -- they instead asserted that they were "pro-girl."
What kind of punk are you?