A fireplace is an architectural

Architecture

Architecture is both the process and product of planning, designing and construction. Architectural works, in the material form of buildings, are often perceived as cultural and political symbols and as works of art...

 structure to contain a fire for heating and, especially historically, for cooking. A fire is contained in a firebox

Firebox (architecture)

A firebox or firepit is the part of the fireplace where fuel is combusted, in distinction to the hearth, chimney, mantel, overdoor and flue elements of the total fireplace system. The firebox normally sits on a masonry base at the floor level of the room...

 or firepit; a chimney

Chimney

A chimney is a structure for venting hot flue gases or smoke from a boiler, stove, furnace or fireplace to the outside atmosphere. Chimneys are typically vertical, or as near as possible to vertical, to ensure that the gases flow smoothly, drawing air into the combustion in what is known as the...

 or other flue

Flue

A flue is a duct, pipe, or chimney for conveying exhaust gases from a fireplace, furnace, water heater, boiler, or generator to the outdoors. In the United States, they are also known as vents and for boilers as breeching for water heaters and modern furnaces...

 allows gas and particulate exhaust to escape. Fireplaces are a central household feature, as the flames and crackling sounds are comforting, http://en.wikipedia.org/w/index.php?title=Fireplace&action=editeven when not necessary for heat or cooking.