Wow it's sad to see so many people get this wrong.
KylieDog is the only one I see that got it right, but I didn't read every post
First Person is viewing the game from the character you control.
Second Person is viewing the game from another character, that which you do not control (rare).
Third Person is viewing the game from the perspective of an imaginary person that is not there. The point is to show you both the character and it's surroundings. Third person is how most movies and TV shows are shot, platformers like Mario can be interpreted to be in third person. The original Resident Evil with it's odd camera fixture is also third person.
Now if there were a game where you view the action from a security camera , and control a character that can be viewed from the camera, then I would consider that Second Person, because there could be a character watching the camera output or not (we wouldn't know unless the game illustrated that). But that's up for interpretation and quite debatable.
