Cold storage has been found have been used as far back as the Roman and Persian empires when caves of harvested ice and snow would be insulated with straw to freeze food during warm periods. Its propose back then is much the the same as it is today, to store and preserve different types of food for year round consumption.
Older cold storage system rely on synthetic refrigeration system based on chlorofluorocarbon (CFC) but in the 1970's it was discovered that the leakage of this type gas was having a hugely detrimental effect on the o-zone layer. The system used in large scale systems is called "Cyclic Refrigeration" and its basic principle is as follows, heat is pumped out of an area by a heat pump (mechanical work) to a higher temperature heat sink, in order to prevent the heat from returning the heat sink may be insulated.
The system used in most household and industrial refrigerators is called "Vapor compression cycle" and it work as follows, a refrigerant is pressurized causing it to become heated, it then enters a condenser were it cools becomes a liquid, it then enters an expansion valve which causes a fast drop in pressure making some of the liquid vaporise back into a gas but allows it to retain its lower temperature. The mixture of gas and liquid then travels to a series of evaporator coils were it cools warm air pushed over it by a fan. This cooling effect returns all of the mixture to a liquid which is is then ready to start the process all over again.