After obtaining a commercial licence, many pilots then work obtain their Instructor Rating. This enables them to teach other students and is the most common way for new pilots to build their flying experience while being paid.
There are different levels of instructor ratings. Category A, B and C. Category C (or C-Cat) is the first.
C-Cat instructors will be under the direct supervision of an A or B-Cat instructor, until they have obtained at least 100 hours of instructing.