When a parasite lives within another organism. The parasite benefits while the other organism is harmed.
the sucking of blood and giving of diseases
The medical term for the occupation and dwelling of parasites on the external skin surface is "ectoparasitism". Ectoparasites are organisms that live on the surface of a host's body, such as fleas, lice, and ticks.
In the animal kingdom, parasitic relationships can be classified into several types, including ectoparasitism, where parasites live on the surface of the host (e.g., fleas on dogs), and endoparasitism, where parasites live inside the host's body (e.g., tapeworms in intestines). Another type is social parasitism, where one species exploits the social behavior of another, such as brood parasitism, where a bird lays its eggs in the nest of another species (e.g., cuckoos). Additionally, hyperparasitism occurs when a parasite itself is parasitized by another organism. Each type demonstrates the diverse strategies parasites use to exploit their hosts.