A camera can move in two or three dimensions. The two-dimensional camera moves are the pan, tilt, and zoom. The three-dimensional camera moves are the dolly, track, and crane.
The audience perceives the camera movement, because it is transferred to the objects in the shot. The objects will move in the opposite direction of the camera move. When the camera pans right, all objects in the picture will move to the left. A tilt up causes objects in frame to move downward.
The same thing happens with three-dimensional camera moves. A track to the left will make objects in frame move to the right and a crane up will make objects move down.