Rain is a kind of liquid which falls on the surface of the earth by gravity from the sky. Water vapor condenses in the Earth's atmosphere, forming clouds. When these droplets are heavy enough, they fall on the earth's surface - this is called rain. Negative charges and positive charges are created when water particles in a thunderstorm break down. Lightning strikes when a cloud with a negative charge collides with another cloud that has a positive charge. Lightning can also strike from the same cloud. However, there is a negative charge on the ground. So when a cloud with a positive charge moves close to the ground or the earth's surface, lightning strikes. These floods are also harmful to nature and cause fatalities. Source: Internet