ICAO Aviation English for Cadet Entry Pilots is designed for cadets who need to improve their English in order to proceed with an application for an airline's cadet programme.  As such this course focuses on the language skills that cadet entry pilots most need, most urgently.

For example ICAO Aviation English for Cadet Entry Pilots doesn't focus on radiotelephony, but it does put a heavy focus on comprehension skills that a cadet entry pilot would need throughout training.  

In contrast a course like ICAO Aviation English for Commercial Pilots is more suitable for pilots who are already working and need to reach or maintain ICAO Level 4/5.