A professional is generally someone who provides advice or a service and is commonly certified by a professional body as belonging to a particular profession (usually due to having completed certain studies or practice).  This could include a lawyer, accountant, plumber, builder, architect or any other profession in respect of which professional liability insurance can be obtained.

A professional doesn’t have to be an individual, they can be a business as we sued our lawfirm and the company we purchased the business off along with the vendor.