What is idempotency?

Idempotence is a property of an operation where multiple repetitions of it produce the same result as a single execution.

Example: if a request to change the state of a device is sent multiple times in a row, the final state remains the same, regardless of the number of repeats.

In embedded systems, this is important for reliability: if a control command is lost or repeated, the device will not enter an inconsistent state.

For example, the command "turn on the light" is idempotent — no matter how many times it is sent, the light will simply be turned on.