A "hot socket outlet" typically refers to an electrical outlet where power is actively supplied. In other words, it's a live outlet that is currently providing electricity. It's the opposite of a "dead" or "inactive" outlet, which doesn't have any power flowing through it.
It's important to exercise caution when dealing with hot socket outlets to avoid electrical shocks or accidents. If you need to work on an electrical circuit, it's recommended to turn off the power at the breaker or fuse box before proceeding.