In OpenMRS core functionality, Users have Roles. Roles consist of Privileges. Privileges determine what a Role (and thus a User that has the role) can do.
For individual modules, it is expected that module developers will code in new Privileges that are relevant for their work. This is true even though Privileges are part of core OpenMRS functionality. More information about coding privileges in general can be found here: Module Privileges and Roles
What the privileges need to do will be explained in user stories.
For testing purposes we have created the following users Dave and Lynette (Password for both: Password01).