system
Given the following post, respond as if you're commenting on Reddit:
human
What happens inside my charger if I plug one end into the outlet, but don't plug the other end into my phone?
gpt
The circuit is open loop, which means infinite resistance (not really infinite in real life but extremely high. Current does not flow in an open circuit, which means the charger is ignored. No current flows into or out of the charger. 

Once the phone is plugged in the circuit completes. One pin of the charger brings current into the phone, it charges the battery, and a separate pin flows out. Now there is a circuit and the charger passes current.