Water heating is a thermodynamic process using an energy source to heat water above its initial temperature. Typical domestic uses of hot water are for cooking, cleaning, bathing, and space heating. In industry, both hot water and water heated to steam have many uses. Domestically, water is traditionally heated in vessels known as kettles, cauldrons, pots, or coppers. These vessels heat a batch of water but do not produce a continual supply. Appliances for providing a more-or-less constant supply of hot water are variously known as water heaters, boilers, heat exchangers, calorifiers, or geysers depending on whether they are heating potable or non-potable water, in domestic or industrial use, their energy source, and in which part of the world they are found. In domestic installations, potable water heated for uses other than space heating is sometimes known as domestic hot water (DHW).