This video will give you a quick run down on the difference between move turn and roll. It is important to understand the difference when using one shots to place and orient your objects and when using procedures to animate objects and subjoints.

Move – will change the position of the object relative to the orientation of the object.
Turn – Will turn the object around its pivot point around the vertical axis. This won’t change the position of the object but will change the orientation of forward and right and left.
Roll – Will roll the object around its pivot point around the forward to back axis. This won’t change the position of the object but will change the orientation of up and down and right and left.