A lighthouse is a navigational aid, typically a tower structure erected in coastal areas or dangerous shoals. Its primary function is to emit powerful light signals, allowing mariners to determine their position and safely navigate hazardous waters. Historically powered by oil or fire, modern lighthouses utilize electrical systems and advanced optics to project highly visible beams. The distinctive sequence and pattern of flashing lights, known as the characteristic, are unique to a specific location, enabling vessels to chart their course relative to the coastline and avoid grounding or collision with unseen hazards.