If I am a water molecule and I am in the physical state of vapor I would rise to higher layers of the atmosphere, where the temperature is lower. Upon reaching a certain altitude, I would go from the state of vapor to liquid (condensation) and form clouds, which are, in reality, a large amount of water droplets.
When rain started, a process also called precipitation, I would start to return to the Earth's surface, at that moment I would be being directly influenced by gravity. That way I could reach rivers, lakes and oceans, infiltrate the soil and rocks or I could be prevented from returning to the earth's surface by vegetation.
After that, sunlight would cause the water present on the Earth's surface to evaporate, causing me to return to vapor form and start the cycle over again.
