Decay, or decomposition, is the natural process where organic materials break down into simpler substances. This happens when living things, like plants and animals, die and their bodies start to decompose. Microorganisms, such as bacteria and fungi, play a crucial role in this process by feeding on the dead matter, which helps recycle nutrients back into the soil. As decay occurs, it contributes to the ecosystem by enriching the soil, making it fertile for new plants to grow. This cycle is essential for maintaining a healthy environment, as it ensures that nutrients are reused. Without decay, life on Earth, including ecosystems and food chains, would be disrupted.