This is simply the various water forms present in the atmosphere, usually falling as snow, rain, sleet and hail. Sometimes, it can represent as fog and may not fall as rain does, but they are all classified as precipitation.
After condensation, the size of water droplets in the atmosphere get bigger as more and more water particles bump into each other. Soon, the fall velocity or the force of gravity is more than the wind or air currents holding it. The water has to come down. Precipitation can be in the form of rain, snow, sleet and hail.
Click on each of the precipitation forms below to see how they differ from each other.
It is important to note that particulate matter (very tiny particles made up of dust, soot and salt) play a very important role in the formation of water droplets. They serve as a nucleus around which the water will settle. This is why rainwater in not always pure, because depending on the particulate matter in the atmosphere, the water may contain various minerals. Some rainwater, such as acid rain, may be harmful.
The amounts of water that fall from the sky vary a lot. Some regions are constantly having rains, whiles others have very little rain all year.