Game Development

Haven't really done much in game design, but if I'm understanding right.

In game design, lets go with 2d first. You mark position with numbers. In 2d you have X and Y. So you say to move to 5,5. then from the starting point that will be 5 right, and 5 up.

3D you have the same thing, but a bunch of different groups were working on it in different ways without working together. So you wound up multiple systems that had X, Y and Z meaning different things. In the majority of 3d systems Y represents up/down. (the other 2 directions are still kind of half and half between systems)