What is the meaning of Payload?

That part of a cargo that produces revenue.

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

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

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

The actual data in a data stream.

Source: wiktionary.org