What is the relationship called when one organism benefits while the other is harmed?

The relationship where one organism benefits while the other is harmed is referred to as parasitism. In this type of interaction, the parasite derives benefits such as nutrients or habitat from the host, while the host experiences some form of harm or detriment, which can range from mild to severe depending on the nature of the relationship.

For instance, many types of worms or pests that attach themselves to a host organism and feed off its resources exemplify parasitic relationships. This contrasts with commensalism, where one organism benefits and the other is neither helped nor harmed, and neutralism, where neither organism is significantly affected by the interaction. Amensalism describes a relationship where one organism is inhibited or destroyed while the other remains unaffected, which also differs from the parasitic interaction.

Understanding these terms is crucial for studying ecological relationships and the dynamics of ecosystems.