A chimney or smokestack, often called a smokestack or stack, is a vertical structure used to dissipate chimney smoke and exhaust combustion gases generated by fuel-burning equipment. Other synonyms for a chimney or smokeshaft include flue, vent, pipe, shaft, funnel, and exhaust pipe. In industrial settings, larger chimneys are called stacks and can be found in power plants and factories. A chimney can also be used to describe a fireplace vent or the pipe leading from a wood stove. Regardless of the type of structure, the purpose of a chimney is to safely redirect harmful gases produced by fuel-burning appliances away from occupants and into the atmosphere.