Division Cyanophyta, commonly referred to as blue-green algae, is a diverse group of photosynthetic bacteria that play a crucial role in aquatic ecosystems worldwide. Synonyms for this division include the phylum Cyanobacteria, which is used to classify these organisms based on their unique pigment composition and cell structure. Other synonyms include the term "algae" itself, as well as the order Oscillatoriales, which refers to a specific group of filamentous cyanobacteria that move by oscillating their cells. Regardless of the term used, the importance of these organisms cannot be overstated, as they produce a significant amount of oxygen and serve as the base of many food chains in aquatic environments.