Science & TechHow it works
Your fridge doesn't make cold. It moves heat.
A compressor squeezes a refrigerant, which gets hot and dumps that heat into your kitchen through the coils on the back. The refrigerant then expands through a valve, turns ice-cold and evaporates inside the cabinet, soaking up heat from your food. The loop repeats as long as the compressor runs.
Useful: That's why leaving the door open won't cool the kitchen: more heat leaves the back than vanishes from the front.
Source: en.wikipedia.org