In petroleum and natural gas extraction, a Christmas tree, or "tree", is an assembly of valves, spools, and fittings used for an oil well, gas well, water injection well, water disposal well, gas injection well, condensate well and other types of wells. It was named for its resemblance to the series of starting lights at a drag racing strip

A Christmas tree is an assembly of valves, spools and fittings used for oil, gas, water injection, water disposal, gas injection, condensate and other types of wells. It is named for its resemblance to a decorated tree at Christmas.