Team Plasma are a team of unknown origin and background that appear in Pokémon Black and Pokémon White. They wear hooded cloaks similar in style to that of English Knights during the days of Camelot. It is unknown what their intentions are of what role they play throughout the games.
The Team Plasma's boss is called "N". He's got long blond hair. He wears 2 goud bracelets (excuse me that I could not find his image). As I zei before it is unknown what their intentions are, but i think that this team wants to capture Zekrom and Reshiram, the legendary pokemon of black and white. Together they are able to create energy necessary to control the world.
I hope i have been helpful. Please comment! =)