A refrigerator is an appliance that keeps food cold to prevent it from spoiling. Inside every refrigerator, a clever system pumps heat out of the box and releases it into your kitchen (which is why the back of a fridge feels warm). This creates a cold environment inside, usually around 37-40 degrees Fahrenheit, which slows down the growth of bacteria that make food go bad.

Before refrigerators became common in the 1920s and 1930s, people relied on iceboxes (insulated cabinets cooled by large blocks of ice), root cellars, smoking, salting, or canning to preserve food. The invention of mechanical refrigeration transformed daily life. Families could buy fresh food less often, waste less, and enjoy a wider variety of ingredients. Grocery stores could stock perishable items, and farmers could ship their products farther than ever before.

People often shorten refrigerator to fridge (notice that we add a “d” when we shorten it, even though there's no “d” in refrigerator). When something needs to be refrigerated, it must be kept cold to stay fresh and safe to eat.