Class Mastigophora is a classification of unicellular organisms that are commonly known as flagellates. The term flagellates comes from the fact that these organisms are equipped with whip-like structures called flagella, which they use for movement. Flagellates are a diverse group of organisms that inhabit a wide variety of environments, ranging from marine and freshwater habitats to the guts of animals. Some common synonyms for Class Mastigophora include "flagellated protists," "flagellated microorganisms," and "flagellated unicellular organisms." Other terms that are used to describe these organisms include "zooflagellates," "phytoflagellates," and "cryptozoic flagellates," depending on the subgroup to which they belong.