1) A wannabe thug, often illiterate and an inhabitant of a downtrodden ghetto that hangs around in "gangs"; largely associated with the African-American subculture. These try-hard wanna be "gangstas" attempt to make themselves appear like real criminals by graffiting buildings, smoking/selling drugs and trying to looking all "bad-ass and macho an'-shit, yo". An utter degradation of what true gangsters represent (see below), and street wannabe "gangsta"-types don't hold a candle to what real gangsters are.
2) The *real* gangsters are those behind organised crime; most notably the Mafia. Responsible for blackmarket trade, epsionage, organised beatings/assassinations, etc. "The Godfather" portrays the archtype of true gangsters, showing the brutality of mob beatings, shootings, running rackets and abusing woman, alcohol and everything in between. The real gansters are *not* to be confused with the aforementioned definition, commonly used as it might be.
2) "All right, you just shot 'em both. Now what do you do?"
"Sit down and finish my dinner."
gangster: "I prefer that you speak english if you do not want me and my boys to see that you are "six feet under" very soon."
wannabe: "Whatchyo talking about, foo! That be some tight sheet!"
gangster: "very well. you have made your choice. I shall see that you get a proper funeral with the fish, so that you do not disturb me any longer."
(shoots him with a machine gun)
Gangbangers:Bloods,Crips, most other South Central street fraternities.
Most of the time they are 30 year olds who haven't gone through puberty, still live with their parents, work in McDonalds for a living, and still believe they're the shit.
They usually require 5 or more people to beat one person up, because they're too much of pussies to fight by themselves.
A waist of space, and an insult to everything.
Person 2: Who gives a shit? Less to worry about.