Hipster means a person who goes after the latest trends and style. It is also a subculture of young, lately established urban middle class white adults and older teenagers who came out in the 1990s. Check outhttp://en.wikipedia.org/wiki/Hipster_%28contemporary_subculture%29 for more information.
A hipster is someone who is the latest and greatest. They wear the most popular clothes, do the most popular things, say the most popular stuff. They just do the newest fads and that pretty much sums it up.