Water is required for the survival of most of the organisms and this means that it is also required for the survival of ecosystems. There are various ways by which water enters the atmosphere. Two of such ways are Evaporation and transpiration. Water from the water bodies gets converted into water vapors due to the heat of the sun. Such process is called evaporation. These vapors then rise up in the air. Similar is the case with the plants. Due to high humidity, heat and wind, plants loose its water in the form of small water droplets. The process is called transpiration. These droplets then become water vapors and rise in the air. Vapors in the air then cools down and condenses to form the clouds. Clouds then precipitate the water in the form of rain, snow or hail.