In such interspecific interaction between the two populations in which one of them is benefited while the other is harmed or even eliminated.
(a) Competition.
It is a negative interaction involving struggle for common requirements between any two species of a bio community to obtain food and shelter chiefly. It goes by the concept of the survival of the fittest resulting in domination of one population and elimination of the other.
e.g. Competition between the carnivores for the similar type of prey.
(b) Predation. It is the exploitation of a species by the other for food. Animal which kills is Predator while the one which is killed is the Prey.
(c) Parasitism.
It is the phenomenon in which organism of one species draws food from the body of another living organism. Parasitism differs from predation in sense that host is not killed by the parasite. However a prolonged parasitism can weaken the host.
