Division Chlorophyta, commonly known as the green algae, is a group of photosynthetic organisms that are mostly aquatic. There are several synonyms for this division, including Chlorophyceae, Chlorophytina, and Chlorobiota. These synonyms represent different taxonomic systems and classification schemes used by scientists to group and differentiate these organisms. The green algae have a wide range of morphological and physiological diversity, and play important roles in aquatic ecosystems as primary producers and as food sources for other organisms. Despite their diversity, the green algae share key characteristics like chlorophyll a and b, cell walls composed of cellulose, and a flagellate stage in their life cycle.