Cyanobacteria are a group of simple, single-celled organisms that can perform photosynthesis, similar to plants. They are often found in water bodies, soil, and even on rocks. These microorganisms are important for the environment because they produce oxygen and can fix nitrogen, making nutrients available for other organisms. Cyanobacteria can appear in various colors, including green, blue, and red, due to the pigments they contain. Some species can form harmful blooms in water, which can produce toxins that affect aquatic life and human health. Understanding cyanobacteria is crucial for managing ecosystems and ensuring water quality.