Class Trematoda: Infect the internal organs of hosts. Parasitic Can be endoparasites (live in the host) or ectoparasites (attach to external surfaces of the host. Size: ~ 1 cm to 10 cm Covered in an unciliated cuticle. Usually require 2 hosts to complete it's life cycle.
The difference between a mole and a wart is that moles are not contagious, but warts are. A mole, or nevus, is a collection of skin pigment cells. When they are small, they look like small brown dots. When the collection is larger, and slightly deeper, it can cause a raised skin colored bump over it.
Not skin tag: Hpv, or human papilloma virus, causes warts, including common warts and genital warts. These are different from skin tags. A skin tag is generally a flap of skin or similar, while a wart is flat. Because warts contain virus, they can be infectious.