Water cooling's a method of heat removal from components. As opposed to air cooling, water's used as the heat transmitter. Water cooling's commonly used for cooling internal combustion engines in automobiles and large electrical generators. Other uses include cooling the barrels of machine guns, cooling of lubricant oil in pumps; for cooling purposes in heat exchangers; cooling products from tanks or columns, and recently, cooling of various major components inside high-end personal computers. T… (More on Water-cooled)