Water cycle is the continuous movement of water in the atmosphere. Water present in ponds, lakes, rivers, seas and oceans changes its form and converts to water vapour due to the heat of the atmosphere (evaporation). As the water vapour rises, the low temperature of atmosphere causes condensation of the water vapour. Tiny drops of water thus formed join together to form clouds. The lighter clouds keep on growing in size. They are moved from one place to another with the help of air. When the clouds become too heavy, it becomes difficult for them to hold water, and this results in rain (precipitation). The rain water gets collected in the water bodies present on the Earth. This whole process of movement of water is called water cycle.
Humidity: The amount of moisture or water vapour present in air is called humidity. Humidity affects the climate of a place. The wind that blows from the sea towards the land brings a lot of moisture with it and makes the weather humid. The places near the sea are more humid than those far away from the sea. Humid weather makes us sweat considerably. Humidity is affected by the temperature of the atmosphere. The air that is warm can hold more moisture than the cooler one. Hence, tropics are more humid than the poles.
