Answer:
An overseer is a person who supervises a work whereas a sub overseer is the substitute or second in command of an overseer.
Step-by-step explanation:
In construction, for example, the Civil Overseer supervises the work done by manual laborers. The Civil sub overseer is a basic-level technician. The Civil Overseer and Sub overseer also differ in qualifications. The sub overseer learns from the overseer who is the main and responsible engineer. In the business setting, an overseer can be likened to a Director while the sub overseer is the Manager.