An industry is usually talking about the market for something, or how well things are selling. a profession is the same as a job.

An industry is a group of companies and organizations that all work on similar things. Some examples: The auto industry is a group of companies and organizations that all work on cars, parts of cars, or other car-related products and technologies. The computer industry is a group of companies and organizations that all work on computers or other computer-related products. A profession is a more general term for a job. For example you could say "He is a brain surgeon so he is in the medical profession." Profession is a tricky term though, it can be grammatically correct in a sentence but still not the right term to use. Watch when it is used and you will get a sense for when to use it.

industry refers to a part of the economy which can be identified by its activities or products. eg the financial services industry or the auto industry. profession refers to a qualified group of people who practice a particular set of skills eg lawyer, dentist, accountant, architect

www.thefreedictonary.com/industry www.thefreedictonary.com/profession