Airline pilot - Airline captain
The ATPL(A) - airline transport pilot license  is required to operate as a pilot-in-command in a multi-pilot aeroplane. For example, Boeing 737 or Bombardier CL65. The ATPL(A) license is not required to fly as a commander on a smaller aircraft operated in multi-pilot environment - so-called single-pilot business jet aircraft, such as the Cessna C525 Citation.
However, holding an airline transport pilot license is one of the prerequisites for becoming a Captain in the multi-pilot aeroplane.