A refrigerator is an electrical appliance used for storing and preserving food at a cold temperature. A refrigerator can also be a cold room used for food storage.
In the early 20th century, refrigerators were called iceboxes. They were large boxes with big blocks of ice in the back that would keep the inside cool.
Modern day refrigerators consist of a compartment that is thermally insulated and works to transfer heat from inside the unit to the back, and simultaneously cools the inside either by chemical, mechanical or electrical means. Refrigerators operate at temperatures between 37 and 41 degrees Fahrenheit.