Explain the working of Refrigerator or Fridge.

Gases heat up when you compress them and cool down when they are allowed to expand. This property of gases is used for making a fridge or refrigerator. 

In a refrigerator, a gas called refrigerant is used for this process.

When refrigerant is made to expand suddenly, it cools down and all the heat from the contents of the fridge. Then it is compressed to increase its temperature. This heat is transferred from the refrigerant to the surroundings.

It works in a cycle and heat is continuously removed from the refrigerator and transferred to the surroundings