Microscopic organisms, also known as microbes, are tiny living beings that cannot be seen with the naked eye. They include bacteria, viruses, fungi, and protozoa. These organisms can be found in various environments, such as soil, water, and even inside the human body. They play essential roles in ecosystems, including nutrient cycling and decomposition. Many microscopic organisms are beneficial, helping with processes like digestion and fermentation. However, some can cause diseases in humans, animals, and plants. Understanding these organisms is crucial for fields like medicine and environmental science, as they impact health and ecological balance.