If you're referring to two magnets being used as part of the refrigerator's design, then these magnets are likely part of the sealing system for the fridge door. Refrigerators use magnetic strips embedded in the door seals (gaskets) to ensure a tight closure.
The magnet's purpose is to pull the door tightly against the refrigerator's body, ensuring that no cold air escapes from the inside. This magnetic seal not only helps to keep the food fresh inside the refrigerator but also makes the appliance energy efficient.
Usually, these magnetic strips go around the entire door edge, so they're effectively "on every side" of the door, not just two sides.
However, if you're referring to external magnets, like decorative or functional magnets people often put on their fridge doors, these are typically used for attaching notes, photographs, reminders, shopping lists, or kids' artworks. They don't have a role in the functioning of the refrigerator itself.