Firstly,from application scope and objects, lightning rods have a wide range of applications, mainly used to protect buildings, tall trees, etc. from lightning strikes, by guiding lightning to discharge towards the lightning rod and introducing lightning current to the ground through grounding devices, the protected object is protected from lightning strikes. SPD (Surge Protection Device) is mainly used to protect electrical equipments and electronic instruments, etc. by limiting the amplitude of lightning overvoltage and surge voltage, it prevents equipments from being damaged.
Secondly, the installation position and mechanism of action are different. Lightning rods are usually installed at the top of the protected object to guide lightning by changing the direction of lightning discharge. SPD is installed on power and signal lines as a supplementary measure for lightning arresters to eliminate direct intrusion of lightning waves, or when lightning arresters do not completely eliminate lightning waves. Its position is often at the end outlet or signal circuit.

Thirdly, from the perspective of protection methods, lightning rods mainly guide lightning through physical means, while SPD restricts lightning overvoltage and surge voltage to protect equipment from damage. In practical applications, appropriate protective equipment should be selected based on specific circumstances to ensure the safety of electrical equipment and buildings.