Water comes out of your faucet and into your sink or bathtub. A faucet is a device that allows you to turn the flow of water on and off.
The faucet is not just the metal part that the water comes through, it is the whole mechanism for controlling the flow of water. If you cry easily, someone might say you are a regular faucet. This is because water comes out of your eyes more often than it does for most people. If you ask your parents a little too often for cash, they might joke that they're going to turn off the money faucet.