What is idempotency in Ansible?

Idempotence in Ansible means that running the same playbook or task multiple times will result in the same outcome without side effects. That is, if the system's state already matches what is described in the playbook, rerunning it will not change the system or cause errors.

For example, if a task creates a user, rerunning it will not create a duplicate but will simply ensure that the user exists.