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.
Warts are generally caused by a human virus known as papilloma while moles are generally related with age and caused by hormones and environmental factors. There are cases when kids are born with moles but in general moles on the face increase with increase in age.
Warts appear in the form of ulcers, sores or vesicles and have a rough cauliflower-like surface, whereas a pimple has a smooth surface with a raised, bump-like appearance. Warts eventually become covered with a scab and crust over. Pimples do not scab. Pimples often have a white center filled with pus.