TOPIC: Differences between change management systems, plans and controls

I'm a little confused the differences between change management systems, plans and controls. I can only understand them as control is a subset of plans which is a subset of systems
or are they all different? I'm trying to understand the differences, an example would really help my understanding. I appreciate any constructive comments.

Hi Duy Tran,
In the PMBOK guide, I think there is mention on "change management plan" which is part of the project management plan. I don't recall seeing anything that mentioned "change management system" or "change management control". Will you be able to explain your rationale behind your question?