What is the difference between get_target_tcp_pose and get_actual_tcp_pose?

What is the difference between get_target_tcp_pose and get_actual_tcp_pose?
It seems the same to me.

Hi,
get_target_tcp_pose() returns the planned position, and get_actual_tcp_pose() returns the actual pose of robot.
if every runs well, they should be nearly the same, if the gap is over the limit, protective stop triggered. picture below for example.