Final answer:
An organism that can easily move to and from its host is classified as an ectoparasite because they live on the host's surface and can transfer between hosts more readily than endoparasites, which reside inside their hosts.
Step-by-step explanation:
The statement "Easily moves to and from its host" describes an ectoparasite. Ectoparasites are organisms that live on the surface of their host, either permanently or temporarily. Unlike endoparasites, which reside inside their hosts, ectoparasites such as ticks, fleas, and lice may have less restricted movement and can therefore move onto and off their hosts with relative ease. Historical cases such as the deer ked show that ectoparasites can sometimes travel with their hosts over distances, but typically, they don't migrate by themselves. They depend on close contact with the host for their life cycle and can persist in a new area if they are able to complete this cycle.
Based on the statement 'Easily moves to and from its host', we can classify it as describing an ectoparasite. Ectoparasites have adaptations that allow them to attach to their host and move around on their body to find food and reproduce.