An Airline Transport Pilot License (ATPL) is the highest level of pilot certification, allowing individuals to act as pilot-in-command of commercial airliners. To obtain an ATPL, candidates must meet specific requirements, including a minimum number of flight hours, passing written exams, and completing a practical flight test. This license is essential for pilots who wish to work for airlines and operate large aircraft. It ensures that pilots have the necessary skills and knowledge to handle complex flight operations and maintain safety in various flying conditions.