A  furnace  is a device used to heat and melt metal ore to remove  gangue . The name derives from  Latin  word  fornax , [1]  which means  oven . The heat energy to fuel a furnace may be supplied directly by fuel  combustion , by electricity such as the  electric arc furnace , or through  induction heating  in  induction furnaces .

In  American English  and  Canadian English  usage, the term  furnace  refers to the  household  heating systems based upon a central furnace, otherwise known either as a  boiler , or a  heater  in British English.  Furnace  may also be a synonym for  kiln , a device used in the production of  ceramics .

In  British English , a  furnace  is an  industrial  furnace used for many things, such as the  extraction  of  metal  from  ore  ( smelting ) or in  oil refineries  and other chemical plants, for example as the heat source for  fractional distillation  columns. The term  furnace  can also refer to a direct fired heater, used in boiler applications in chemical industries or for providing heat to  chemical reactions  for processes like cracking, and is part of the standard  English  names for many metallurgical furnaces worldwide