I want to know the question between a job overview and a job description. Help!

Job overview = general information, including the tasks other employees may be asked to do (sweep the floor, disinfect the telephones, keep the bulletin boards current, plunge a stopped-up toilet, etc.)

Job description = specific tasks of a particular job

And it also can make a difference depending on the company you work for. Different companies will use various terminology incorrectly at times.

Context can make a difference, how was the term used?