Basic Empty Weight (BEW): the weight of the aircraft as it sits in front of you including oil and other fluids, not NOT FUEL.

Useful Load: the maximum allowable gross weight of the aircraft MINUS the BEW.

Payload: the maximum allowable gross weight of the aircraft MINUS fuel weight and MINUS the BEW.

Maximum Ramp Weight: the maximum weight at which the aircraft can be taxied.

Maximum Take Off Weight: the maximum weight at which the aircraft can become airborne.

Maximum Landing Weight: the maximum weight at which the aircraft can land.

Maximum Zero Fuel Weight: the maximum weight at which the aircraft can be loaded without accounting for fuel weight.