What is Job?

Legal Definition
A person's job is their role in society. A job is an activity, often regular and performed in exchange for payment. Many people have multiple jobs (e.g., parent, homemaker, and employee). A person can begin a job by becoming an employee, volunteering, starting a business, or becoming a parent. The duration of a job may range from an hour (e.g., odd jobs) to a lifetime (e.g.,judges).

An activity that requires a person's mental or physical effort is work (as in "a day's work"). If a person is trained for a certain type of job, they may have a profession. The series of jobs a person holds in their life is their career.
-- Wikipedia
Legal Definition
By this term is understood among workmen, the whole of a thing which is to be done. In this sense it is employed in the Civil Code of Louisiana, art. 2727; "to build by plot, or to work by the job," says that article, "is to undertake a building for a certain stipulated price." See Durant. du Contr. de Louage, liv. 8, t. 8, n. 248, 263; Poth. Contr. de Louage, n. 392, 394 and Deviation.
-- Bouviers Law Dictionary
Legal Definition
The whole of a thing which is to be done. "To build by plot or to work by the job, is to undertake a building for a certain stipulated price." Civ. Code La. art. 2727.
-- Black's Law Dictionary