A phylum of photosynthetic EUKARYOTA bearing double membrane-bound plastids containing chlorophyll a and b. They comprise the classical green algae, and represent over 7000 species that live in a variety of primarily aquatic habitats. Only about ten percent are marine species, most live in freshwater.

A subdivision of green algae in the division CHLOROPHYTA, subkingdom VIRIDIPLANTAE.

Synonyms: Chlorophytina, txid3041, Green Algae, Chlorophyta, Algae, Green