Some people make a distinction between a job, for which a person just labors at this or that for pecuniary rewards, and the type of work a person might do all their lives, derive self-esteem, and benefit society.

On a grammatical level, "job" is countable, but "work" is uncountable.

The word 'job' relates to a particular work activity. 'Work' is something you do as part of your job. Also, work can be used as a noun and verb. The word 'job' can only be used as a noun.