FPS - First person shooter. Three words, one genre and a whole host of games; it's almost the de facto style for a PC game today. That's you holding that gun, casting the spell and swinging the sword; you get to choose exactly where you look, touch and move to. It's the closest you can get to that virtual world.
Shooting games have been around since... well, if electricity was around when Noah was rebuilding after the floods, Yougamers.com bets money that they'd be playing a shooting game of some kind. Fairground attractions have offered the punter the chance to pop a cap in a duck's head for nearly a century now and there's no denying that it's the most popular activity in games (e.g. Action Man or Cowboys 'n' Indians all involve the use of guns).