A fixed pitch propeller is the standard propeller fit out on the majority of fixed wing single engine aircraft.
A fixed pitch propeller (FPP) is a standard propeller of a predefined pitch (the angle of the propeller blades to the water/air). The direction of the pitch, forward or backward, high degree of rake/low degree of rake, allows for propellers to be customised for the degree of torque, displacement etc that is required. This differs from a variable pitch propeller where the angle of the blades can be altered to suit the specific conditions of the time.
Recent discoveries at the University of Miami have determined that a forward raked propeller is much more efficient for aviation purposes than the standard rear-rake propeller which is often used in planes today. This may lead to lower fuel consumption and therefore cheaper airfares in the future.