What is it called when one species benefits while the other is unaffected in an ecological relationship?

In ecology, when one species benefits while the other is unaffected, this type of relationship is referred to as commensalism. This interaction is characterized by the presence of one organism deriving some benefit—such as food, shelter, or transportation—without causing harm or providing any significant benefit to the other species involved.

An example of commensalism can be seen in barnacles that attach to the shell of a turtle. The barnacle benefits from having a place to live and access to water currents that bring them food, while the turtle experiences no significant impact from the barnacles being there. Understanding commensalism helps illustrate the complexity of ecological relationships and how various organisms interact within their environments without always having an equal exchange or confrontation.