The project coordinator is the right hand of the project manager, when the project manager is overloaded, the project coordinator will start taking over the less important tasks in order to relieve the project manager. This will lead to an increase in the productivity.
Your question "can a project manager be the same person as the project coordinator?" does not make a lot of sense, because the purpose of the project coordinator is simply to relieve the project manager.
If you want a list, here's one:
- The project manager reports to the project sponsor, the program manager, and other stakeholders, the project coordinator reports to the project manager.
- The project coordinator role does not exist in all projects, but a project manager role must exist in all projects.
- The project coordinator is definitely paid less than the project manager.