WHAT IS THE DIFFERENCE BETWEEN CPP AND FPP?

CPP propeller blades can rotate around their axis, FPP is fixed and can't rotate.

CPP – Controllable Pitch Propeller
This is a type of propeller with blades that rotate around their own longitudinal axis and influence the direction of thrust.

FPP - Fixed Pitch Propeller
This is a type of propeller with fixed blades that cannot rotate.