The leaves are compound when they are subdivided into several separate leaflets:

They can be:
1) Pinnate, when the leaflets are arranged along a main axis:

2) Palmate when the leaflets originate from a single point at the top of the leaf-stalk:

3) A particular case is that of '3-foliolate leaves', which are subdivided into 3 leaflets only

The leaves are called simple when they are not subdivided into separate leaflets...:

...even if in some cases the leaf-blade is deeply lobed: