For tax purposes, "Professional" means that you were a Lawyer, Engineer, Notary, Veterinarian, Chartered or certified accountant, Physician, Bookkeeper, Surgeon, Architect, Chiropractor, or Psychologist. If you are one of those, enter your box 048 amount as "Profession Fees". For other professions or businesses, you would enter your box 048 amount as "Business Fees".
FYI: When you enter an amount on (either) box 048 of a T4A, then TurboTax will automatically create a business form (T2125) for this amount.