Hipster in the contemporary sense is a subculture of men and women generally in their 20's and 30's. Aspects of this sub culture include rampant consumerism of "ironic" or "kitschy" pop culture items and art, examples of this include large colored sun glasses, indie music, street art. The nihilistic and self indulgent characteristics of this group have grown and developed from the failure of past youth cultures i.e beats, hippies, and punks to make any sort of true cultural or political change. Thus the hipster culture is an acceptance of all the things which previous countercultures believed they were fighting against such as commercialism and consumerism.
Those hipsters over there dress ridiculous and don't care about anything.