'Vocational' education is often more related to trades (HVAC or heating/cooling technician, electrician, plumbing, electronics certificate, welding, truck drivers, etc) or sometimes things in the medical field like being a certified nursing assistant (CNA). In the US, often this stuff will be done at a community college or through a particular labor union (pipefitters, steelworkers, plumbers, etc). You may receive a certificate or sometimes an Associate's degree for some programs.There may be local programs through a community college to help prepare people for jobs that are needed locally. Usually this training does not include a Bachelor's degree. 'Professional' usually refers to specific types of university degrees like lawyer, doctor, dentist, optometrist, engineer, pharmacist, librarian, accountant, etc. Often these are advanced degrees that are obtained beyond the bachelor's level. In the US, high school is 'secondary' school, so it should be 'post-secondary' vocational or professional education to refer to training after getting your high school diploma.

There used to be a distinction between an "academic" course of study and a "vocational" one at the secondary (high school) level in the US. Students who were perceived as not having the academic potential to succeed at the collegiate (university) level were steered toward "vocational" programs where they would be prepared for blue collar jobs as electricians, carpenters, plumbers, auto mechanics, etc.

Hi there. Great question. I'm going to answer from a United States perspective, as those words can mean different things in English. There's two parts to this question - first dealing with primary versus secondary education. Primary usually refers to elementary school, and secondary means high school. Professional and vocational mean the same thing. There may be slight differences between the two words, but they're meaningless in practical communication. There is really no such thing as 'secondary vocational education' in the United States. Only 'higher education' or 'college education' is vocational by definition in the United States. Now a person might BE a 'professional' high school teacher. But you would never call someone a 'professional high school teacher' because in the US, teachers get paid. So if they ARE a secondary educator, there's no need to state they are professional, because that ought to be assumed.