The diagram below shows the water cycle, which is the continuous movement of water on, above and below the surface of the Earth.

The picture illustrates how water circulates in a cyclical manner, which is known as the water cycle. Overall, the process involves three main stages, namely evaporation, condensation and precipitation, through which the earth gets and maintains the levels of its surface and ground water. Notably, all three forms of water can be seen in this continuous process. First, as the sun shines in the day time, the surface of oceans gets heated, and the water is converted in to the vapor. As the resulting water vapor is light, it goes up, which is known as the evaporation. Importantly, 80% of the atmospheric water vapor comes from the oceans in this way. After being evaporated, condensation takes place, in which vapor particles combine together to form clouds higher in the sky. When clouds are overloaded and becomes heavier, it accounts for precipitation, whereby water returns to the earth in the form of either rain or snow, from which lakes are filled with and mountain tips are usually covered with, respectively. Once precipitated, certain percentage of water flows on the earth’s surface, known as surface run off, ultimately goes in to rivers and finally to oceans, from which salt water intrudes at merging points. In addition to the surface water, a certain proportion of water is absorbed by the ground and known as the ground water, which can be found above the impervious layer of the earth.