Why is there lightning?

Lightning is caused by the static electricity generated by the water vapor in the cumulonimbus cloud, which leads to the voltage difference between the cloud and the ground. When the voltage difference is large, it will break through the air, causing the air to expand and explode in an instant, giving off heat and light. The light is lightning, and the loud sound from expansion and explosion is thunder.

according to different terrain and meteorological conditions, lightning can be generally divided into three categories: hot lightning, front lightning (hot front lightning and cold front lightning) and terrain lightning.