Cestoda is a class of parasitic flatworms commonly known as tapeworms. They are characterized by their long, segmented bodies, which can grow to several meters in length. Tapeworms typically inhabit the intestines of their hosts, which can include a variety of animals, including humans. They absorb nutrients directly through their skin, as they lack a digestive system. These organisms reproduce by producing numerous eggs, which are released into the environment through the host's feces. The eggs can then be ingested by intermediate hosts, such as pigs or cattle, where they develop into larvae. When these larvae are consumed by definitive hosts, they mature into adult tapeworms, continuing the life cycle.