One of our most valuable natural resources is water. There would be no life on Earth without it. Hydrology developed as a science in response to the necessity to comprehend the earth's complicated water system and assist in the resolution of water issues. Hydrology is the study of the Earth's waters, including their occurrence, distribution, and movement through the hydrologic cycle, as well as their interactions with living beings. It also covers the chemical and physical properties of water in all of its forms. The study of the link between water and its surroundings is the major goal of hydrology. Hydrology focuses on precipitation, evapotranspiration, runoff, and groundwater since it is primarily concerned with water near the land surface. A hydrologist is a person who studies water on Earth and how humans interact with and use it. Hydrologists rely on their knowledge of how water interacts with its surroundings, such as how it travels from the Earth's surface to the atmosphere and back.