The boiler is a kind of energy conversion equipment. The energy input to the boiler is chemical energy and electric energy in the fuel, and the boiler outputs steam, high temperature water or organic heat carrier with certain thermal energy.
The original meaning of pot refers to a water container heated on a fire, and a furnace refers to a place where fuel is burned. A boiler includes two parts: a pot and a furnace. The hot water or steam produced in the boiler can directly provide the required heat energy for industrial production and people's lives, and can also be converted into mechanical energy by a steam power device, or converted into electrical energy by a generator.

Boilers that provide hot water are called hot water boilers, which are mainly used in daily life, but there are also a few applications in industrial production. The boiler that produces steam is called a steam boiler, often abbreviated as a boiler, and is mostly used in thermal power stations, ships, locomotives, and industrial and mining enterprises.