In IK animation, an additional node that is created automatically when an IK handle is created. The IK handle is connected to the end effector. As you pose the IK handle, the end effector drives the IK chain. By default the end effector is located at the last joint of an IK chain, but it can be moved to make the IK handle appear to be at a different point in the skeletal hierarchy.
An example is an arm with joints created at the shoulder, elbow, forearm and wrist. The IK chain goes from shoulder to forearm. Moving the end effector to the wrist puts the IK handle in a more intuitive location for the animator.
See also FBIK effector.
