What is the difference between controllers and compensators
While searching for answer the most prominent answer I got was that compensator have magnitude=1 and is used to make sure the system fulfill its requirements (G.M.,settling time etc.) while controller makes sure that output tracks the reference input.
If I consider the above difference valid I still don't get that what is tracking and reference input mentioned.
Please also mention the positions of placement of compensator and controller in a basic control system blocck diagram