Diatoms are tiny, single-celled organisms found in oceans, rivers, and lakes. They belong to a group called phytoplankton and are essential for the ecosystem because they produce oxygen through photosynthesis. Diatoms have unique, glass-like cell walls made of silica, which give them intricate and beautiful shapes. These microorganisms play a crucial role in the food chain, serving as a primary food source for many aquatic animals, including zooplankton and small fish. Additionally, diatoms are used in various industries, such as filtration and abrasives, due to their hard, durable shells.