Refrigeration is the process, or the whole system, of making food or liquid cold so it keeps. A kitchen fridge is a small refrigeration machine; a supermarket has a refrigeration system for meat and milk; engineers talk about refrigeration when they mean the science and the equipment, not just the box in the corner. Though actually, in everyday life people rarely say the word unless a cooling system has broken, or they are explaining why food went bad in a power cut. The meaning on the packet is still “keep it fridge-cold to preserve it,” not “turn it to ice.” In shops and factories, though, refrigeration can cover a bigger cooling plant, including rooms that are colder than a home fridge.