Clouds are made up of millions of water droplets that have condensed from water vapor. Air currents and wind keep the droplets of water in the sky. As the droplets bump into each other, they join together. This makes them larger and heavier. When they get heavy enough, they fall to the ground as rain.
Snow is different.
In cold places, the water vapor freezes into crystals. When many of these little crystals gather together, they become heavy enough to fall as snow. Inc. All rights reserved.