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.