Definition of "payload"

That part of a cargo that produces revenue.  examples

The total weight of passengers, crew, equipment, and cargo carried by an aircraft or spacecraft.  examples

That part of a rocket, missile, propelled stinger, or torpedo that is not concerned with propulsion or guidance, such as a warhead or satellite.  quotations  examples

(computing) The functional part of a computer virus or another type of malware program, rather than the part that spreads it.  examples

(communication) The actual data in a data stream.  examples