What is Change Management?
Change management is the people side of change. It's the work of moving an organization from how things run today to how they'll run tomorrow, on purpose rather than by accident.
Whenever you introduce something new, a technology, a process, a structure, a strategy, a policy, a way of working, people have to make that move. Change management makes the move deliberate. Project management builds and delivers the change.
Change management gets people to adopt it. Both matter. Only one of them is usually staffed.