This feature determines how many separate cooling circuits the refrigerator has. The refrigeration circuits are responsible for maintaining the temperature in the fridge and freezer. A refrigerator can have a single circuit, where it cools both the refrigerator and freezer with one circuit, or double circuits, where the refrigerator and freezer are separate and have their own circuits. Multi-circuit refrigerators allow for better temperature control and increase cooling efficiency, which is useful for those who want to keep different foods at the right temperature.