Air Transport Pilot Licence ( ATPL )
Frozen ATPL means someone who holds a Commercial Pilot Licence (CPL), and an Instrument Rating (IR), and has passed all the Air Transport Pilot Licence (ATPL) theoretical exams. It allows you to act as co-pilot on a multi-crew aircraft.
One you have achieved 1 500 hours, the ATPL becomes unfrozen, and you could, move over to be an airliner Captain. The aim of the PPL training is to teach the student pilot to fly safely and efficiently by day that will lead to the continuation towards the Commercial Pilot Licence.