A compact refrigerator (often called a "mini fridge" or "compact fridge" for short) is a small sized refrigerator that is used to cool the contents inside to below room temperature. Food spoils much slower when kept at a lower temperature.
Compact refrigerators are usually used in small areas like apartments or dorm rooms, they can also fit in small spaces like kitchen nooks, underneath the sink, or in conjunction with a microwave. Sizes can vary from 1.7 to 4.5 cubic meters. Most compact refrigerators offer the same amount of features as a full sized refrigerator except for the specific compartments you'd normally see in a full sized upright.