People with specialized training in certain types of work, either have a:
Trade: these are manual jobs. Examples include carpenters, auto mechanics, hairstylists, and bakers. Butchers, plumbers, and tree surgeons are also trades. To become a tradesperson, you usually have to do a course and complete a period of practical work.
Profession: for this type of job you need a university qualification. Examples include lawyers, doctors, dentists, architects, librarians, engineers, and pharmacists. Scientists, physicists, teachers, university professors, and geologists are also professions. Between trades and professions, there are technical and administration jobs. For some of them, you need a university degree.