Hey there
"Change Management" is an ambiguous term in the world projects.
Techncially change management refers broadly to any change activity that faciliates transition from one state to another.
In my experience this phrase usually means changing business processs or organisational structure, and the change is focused n the impact on the people. It is often a part of automation, workflow or outsourcing projects.
Change control is also often referred to as change management. CHange control is where a request is made to a project to change something hey are doing; eg add new features to an IT system being built, or to include the new sales team in the rollout of the CRM systems, etc. Change control is about applying structured decicion making and analysis to these requests so that projects are able to manage their workload poperly.