They're two different routes to a CPL. The flight test is exactly the same, and the licence you get is exactly the same.
One way to get a CPL is to do 150 hours (minimum) of training before the licence test. Every flight is a training flight - some dual (with an instructor), and some solo (no instructor. You're the pilot in command). Every hour (that you wish to credit towards the CPL) has to be part of the 150 hour course.
The other way is to accumulate 200 hours of experience. Some will be from the various bits of training that you do, and the rest from any other flying that is done.
The idea is that a structured course needs fewer hours to reach the required standard *and* expose the student to sufficient flying experience to develop skill & judgement because every hour is planned towards meeting those requirements. Alternatively, a pilot can get equivalent exposure to develop skills & judgement from various other types of flying, but the more time needs to be allowed to give sufficient opportunity for enough experience 'events' to have happened. Remember, we learn from our experiences.
In Oz, there are restrictions about what hours can be credited towards the 150 hour CPL. Previous flying experience can't always be credited towards a 150 hr course. In some cases it can be cheaper for a PPL holder to get a CPL via the 200 hr 'ad hoc' method because every hour can be credited towards meeting the minimum experience, unlike the 150 hour route.