Think of the radiator in a car.
Hot engine coolant flows through metal tubes in the radiator. And cool air flows around the outside of the tubes.
Since the coolant is at high temperature, and the surrounding air is at a lower temperature, heat flows from the coolant into the metal tubes, and from the metal tubes into the surrounding air.
Devices like radiators are called heat exchangers. They allow a liquid or gas to flow through the tubes, and give up or receive heat from the surrounding air, without the fluid touching or mixing with the air.
In your refrigerator, there are two heat exchangers.
One is located in the freezer and removes heat from cold air in the freezer into the cold Freon gas inside the tubes. This heat exchanger is called an evaporator.
The opposite is true, too… if the fluid in the radiator is COLDER than the surrounding air, heat will flow FROM the air, through the tubes, and INTO the fluid.
The other heat exchanger is located outside of the refrigerator and transfers heat from hot Freon gas inside the tubes into the ambient air. This heat exchanger is called a condenser.
Both of them look a lot like the radiator in your car. They are simply tubes with a lot of fins attached to speed up heat transfer.
The condenser and evaporator transfer heat out of your freezer, and into the outside (ambient) air.