Can you explain what the term idempotency means in the context of working with data and systems?

Idempotency is a property of an operation where multiple executions lead to the same result as a single execution. In the context of data and system operations, it means that repeated calls to the same operation will not further alter the system's state.

For example, the HTTP PUT method is idempotent: if you send multiple update requests for a resource with the same data, the resource's state will remain the same as after the first request.

This is important for ensuring system reliability and predictability, especially in cases of retries due to failures or timeouts.