Lightning protection systems control electrical discharges by directing them through a low-resistance path to the ground, avoiding passage through parts of a structure and reducing risk of fire or other damage.
Air terminals are fastened to the building to intercept electric discharges which might otherwise strike a building component itself, such as a chimney or metal roof.
Electrical discharges striking the air terminal are directed through heavy duty metal conductors to a grounding system (rods driven into the soil) and thence into the earth.