A project is a group of one or more users. In Cloud Computing, a project owns virtual machines. In Object Storage, the project owns buckets. Users can be associated with more than one project. Each project and pair of users can have a role associated with it.
You can manage projects, users and roles independently.
During registration, at least one project, user, and role are defined. You can assign one or more projects to a user, and change or remove an assignment.