Receptors, also known as sensors, are specialized structures in living organisms that detect changes in the environment. They respond to various stimuli, such as light, sound, temperature, and chemicals, allowing organisms to perceive their surroundings. Receptors play a crucial role in processes like vision, hearing, and taste, enabling organisms to react appropriately to different situations. These receptors can be found in various forms, including photoreceptors in the eyes, which detect light, and chemoreceptors in the nose and tongue, which sense chemicals. By converting external signals into electrical impulses, receptors help the nervous system process information and coordinate responses.