Phylum Bryozoa is also commonly referred to as Ectoprocta, a term that is derived from Greek words meaning "outer anus." The term is used to describe the phylum's unique characteristic of having an anus located outside of the body. Bryozoa is also known as moss animals or sea mats due to their colony-forming ability. Another synonym is Polyzoa, which refers to the phylum's ability to form many small cells or zooids within each colony. The phylum is also sometimes referred to as the live corals to distinguish it from the non-living coral structures found in the ocean. Ultimately, all of these terms are used to describe the same fascinating and unique group of aquatic organisms.