Pictured here is one of the countless Stormtroopers, quite commonly seen around and about in 'A New Hope', 'The Empire Strikes Back' and 'Return of The Jedi'. However, I am not familiar with who owns the white, hooded robe to the left of the Stormtrooper.

To find more information about the Stormtrooper and other, more specialized versions, please visit the official following web site's pages at:
http://www.starwars.com/characters/stormtroopers/
http://www.starwars.com/characters/biker_scouts/