When I left school in 1962, we were aware that one route to a secure career was to become a member of a profession.
Professionals were qualified by examination and experience to practice and were members of a professional institute.or association.
The important advantage of having a professional qualification was the ability to become self employed.
There were only nine major professions - doctor, dentist, vet, architect, chartered engineer, chartered surveyor, chartered accountant, actuary or lawyer. (the legal profession could be divide into solicitors and barristers in England or solicitors and advocates in Scotland- so maybe 10 major professions)
Obviously there were many other professions - like clergy, employed by churches, or professions ancillary to medicine. like nursing, physiotherapy, pharmacy, etc, occupations ancillary to architecture - like architectural technology, town planning, conservation advisors, etc, professions ancillary to law and accountancy, like stockbrokers, legal clerks, accounting technicians, financial advisors, etc.
There were other professions like teaching or university academic staff, senior civil servants and military officers, who were undoubtedly professional in the sense that they did require qualifications, but these people were not usually self employed.
Are the traditional professions of any relevance today?