This is when water that is so heavy it falls as solid / liquid

There are about 1.4 billion km3 of water (336 million mi3 of water) on Earth. That includes liquid water in the ocean, lakes, and rivers. It includes frozen water in snow, ice, and glaciers, and water that's underground in soils and rocks. It includes the water that's in the atmosphere as clouds and vapor.

If you could put all that water together - like a gigantic water drop - it would be 1,500 kilometers (930 miles) across.

The vast majority of the water on Earth, about 97% of it, fills the ocean. About 2% of the water on Earth is frozen in ice sheets near the poles and in glaciers. Most of the ice is in Antarctica, a smaller amount in Greenland in the Arctic, and a tiny fraction in mountain glaciers around the world. Most of the remaining 1% of Earth's water is underground, in shallow aquifers, as soil moisture, or deep underground in rock layers. Only a small fraction of the water on Earth (0.03%) is in lakes, wetlands, and rivers.

Water falls from clouds when it condensates. This process is called condensation.