Job and occupation are basically the same, though the word job is a little more informal. In conversation, you say you have a job. On a resume, you list your occupations. Job and occupation can mean short term, but not always. Your profession is something you do for your career, as the main occupation of your life. You can have a job at a shoe store or a fast food restaurant or a bank, etc, but your profession is a teacher or a pilot, something you really want to do. Vocation is similar to profession, but it implies something you are good at. So if you're a good singer, your vocation might be an opera star or a Broadway star. But if you can't find work as a singer, you might have to have a job as a waiter, temporarily until you can work at your vocation/profession of singing. I had a job as a bartender when I was in my twenties. From 1989-1991, my occupation was that of copywriter. (written on a resume, perhaps) For 50 years, my profession was to teach young students. My vocation is a singer.

JOB (synonym) work (definition) refers to a role that includes the physical and social environment of the labor performed by an employee in exchange for a salary. OCCUPATION (synonym) activity (definition) an action that a person spends time doing. PROFESSION (synonym) career (definition) a type of task that requires special education, training or skills. VOCATION (synonym) art (definition) a strong desire to spend your life doing a certain kind of work.