Here's why:

* Water vapor: This is the gaseous form of water, invisible to the naked eye.

* Cooling: As the temperature of the water vapor decreases, the molecules slow down.

* Condensation: The slower molecules lose energy and are no longer able to stay in their gaseous state. They clump together and form tiny water droplets, which we can see as clouds, fog, or dew.

This process is crucial for the water cycle, as it allows water vapor in the atmosphere to return to the Earth's surface as precipitation.