World Units.
As the size of a world is relative to the objects in it, you can't have a specific size unit.
For example, if you created a matrix 1000 units x 1000 units and placed a cube 10x10x10 on it, you might decide that a unit is 1cm - making the cube 10cm x 10cm.
If you now place a model of an ant next to the cube, but make it twice the size of the cube, the camera position can be placed to make it look like a normal sized ant and a really tiny cube - or a normal sized cube and an enormous ant.
See what I mean now about all sizes being relative?
So, we talk about World Units. Therefore, with Move Object, the distance the object
appears to move depends on the scale of the world and the objects in it.
If it's small, then you move the objects a small number of units - or even a fraction of a unit (ie Move Object 1,0.01).
If you have a huge world, then you may have to use Move Object 1,10 to even see it move.
Hope that helps...
TDK_Man