the front part of a guided missile or rocket or torpedo that carries the nuclear or explosive charge or the chemical or biological agents
"The warhead at the tip of the intercontinental ballistic missile is its payload, designed to deliver a massive nuclear charge to the target."
That part of a cargo that produces revenue.
"The airline's profitability depends entirely on its payload, as it is strictly defined as the portion of the aircraft's total weight that generates revenue through passenger tickets and freight sales."
In plain English: Payload is the actual cargo or useful items carried by something, separate from its own weight and equipment needed to move it.
"The rocket was designed to carry a heavy payload into orbit."
Usage: In technical contexts, payload refers to any useful load carried by a vehicle or system, whereas in business and logistics, it specifically denotes the portion of cargo that generates profit. Avoid using this term for general freight unless you are distinguishing between profitable goods and non-revenue items like ballast.
The word payload combines the elements of paying and loading to describe a cargo or data carried by a vehicle. It has been in use since the early 20th century.