A supervisor, or lead, is the job title of a lower-level management position and role that is primarily based on authority over workers or a workplace. A supervisor can also be one of the most senior of the employees at a place of work, such as a professor who oversees a Ph.D. dissertation. Supervision, on the other hand, can be performed by people without this formal title, for example by parents. The term supervisor itself can be used to refer to any personnel who have this task as part of their job description.