Anyone know the difference between gliding joints and ellipsoid joints?

Question

anonymous · Answer

With an ellipsoid joint, the circumference of the joint is an ellipse with the articular surfaces longer in one direction than the other. Therefore, the range of movement is very wide in almost all directions. It is a lot wider than the range of a gliding joint which normally allows movement in one direction. 
ex. ellipsoid joint is like the wrist
ex. gliding joint is like the joint in between the head and the spine.

anonymous · Answer

and is it gliding joint only on flat surfaces?