Excretion is the biological process by which living organisms remove waste products from their bodies. This process is essential for maintaining internal balance and preventing the buildup of harmful substances. In humans, excretion primarily occurs through the kidneys, which filter blood to produce urine, and through the skin, which eliminates sweat. In addition to humans, many other organisms also excrete waste. For example, plants release oxygen and water vapor during photosynthesis, while animals may excrete waste through various means, such as feces or gills. Overall, excretion is crucial for the health and survival of all living beings.