If your are in a cold climate with freezing temperatures you can help prevent your outside faucet from freezing by using a faucet that is especially designed for the outside. It looks like a regular faucet that can be turned on and off from the outside but it is equipped with a very long stem that shuts the water off on the inside where it has less chance of freezing. They are called anti-freeze faucets and can be found at most home centers.
Preventing outside faucets from freezing