A lightning rod (US, AUS) or lightning conductor (UK) is a metal rod mounted on a structure and intended to protect the structure from a lightning strike. ... The lightning rod requires a connection to earth to perform its protective function.
Lightning rods were originally developed by Benjamin Franklin. A lightning rod is very simple -- it's a pointed metal rod attached to the roof of a building. ... If lightning strikes, the system attempts to carry the harmful electrical current away from the structure and safely to ground.