We're all used to rain, but we may not know where it comes from.
To understand this, you have to know that water can be in three forms: it can be liquid, like raindrops, but it can also be solid – when we call it ice or snow. There is also another kind of water that we can't see. We call it moisture or water vapour. It is all around us in the air.
When it gets cold, water vapour changes to liquid water and forms raindrops.
