How do video game cameras work?

[darkely]

So pretty much in Amnesias case you technically are the camera. Well I am more interested in third person cameras like in Dead Space...

Image: http://i.imgur.com/JP7oI.jpg

The camera can spin around the player (all the way) however the camera when looking forward is always slightly to the right of the player. Is this to give the player room to see what is going on or what?