Parenting locks an object to an main object so that whatever changes made to the parent object will also affect the child as well.
The child on the other hand can move independent even when parented to an obj.
While this can be use to animate an object, this will be tricky when we try to animate bi-peds, quad-peds or anything which has an arm like movement. So, in this case we use the IK/FK rigging
Bones
Bones as the name suggest is placed underneath the mesh for rigging. it is the one which is going to control the geometry which lies above
The movement of the geometry is achieved by parenting the bones with the geo.
IK Handle
Through IK handle we can get arm like movement in the geometry, without needing to animate each geometry manually.
For characters like human, maya has auto rig option which is much more easy to use
