Three Dimensional Frame
The game world is visually represented to the player using three dimensional graphics. That is, it's represented as having height, width and depth, like the "real world" we all inhabit. The dimensionality of the camera is independent of the dimensionality of the game's world. That is, a three dimensional camera may be used to depict gameplay that takes place on less than three dimensions.
Super Mario 64
Super Mario 64 [Miyamoto, 1996] places Mario in a 3D world represented in three dimensions. Objects in the world are represented as having three dimensional volume (height, width and depth).
Miyamoto, S. (1996). Super Mario 64. Nintendo, nintendo 64 edition.