The water cycle
The water cycle is a process, water goes through between land, sea and atmosphere. The water is recycled throughout the process, the water also changes state throughout the process. It can change to a liquid, gas or a solid and then change back again. The steps in the water cycle are evaporation, condensation, precipitation and groundwater/runoff.
One of the most important steps is Evaporation. Evaporation is an invisible process where the sun heats up the water and then that turns into vapor. The sun's energy breaks the bonds that hold liquid water molecules together. So, it makes sense that water evaporates more easily in hot conditions, such as in the desert, rather than on a cloudy winter day, this is called humidity. After the water turns into vapor it floats and forms into clouds which is called condensation.
The next step in the water cycle is Condensation and Precipitation. Condensation happens because of temperature changes (becomes hotter). Warmer air can contain more water vapor than colder air, so when air rises up from the heated earth's surface high into the sky to where the temperatures are much colder, condensation happens. You can sometimes see condensation on your window/glass it will fog up the little droplets will form. Precipitation is where air is full of water, even if you can't see it. Higher in the sky where it is colder than at the land surface, invisible water vapor condenses into tiny liquid water droplets-the clouds you see everyday. When the cloud droplets combine to form heavier cloud drops which can no longer float in the surrounding air; it can start to rain, snow, and hail all forms of precipitation.
After that is Runoff and Groundwater. Groundwater moves underground and due to gravity, it moves downward and sideways. Groundwater serves many purposes in nature: keeping plants alive, filling aquifers, from which people can withdraw water, providing water to rivers and lakes, and eventually flowing into the oceans; Runoff happens after water has fallen or snow has melted, the water follows gravity and falls down into streams, rivers and oceans and then the process repeats again and again never stopping.
Overall the water cycle is a step by step process that recycles and re-uses water, we get clean and fresh water because of this. The steps (evaporation, condensation, precipitation and groundwater/runoff) have no end and no start.