What term describes a symbiotic relationship between two different species where one benefits and the other is unaffected?

The term that describes a symbiotic relationship where one species benefits while the other is unaffected is commensalism. In this type of relationship, one organism derives some benefit, which could be in the form of food, shelter, or other resources, while the other organism neither gains nor loses from the interaction.

For example, barnacles that attach to the shell of a turtle exemplify commensalism; the barnacles benefit from the mobility and feeding opportunities provided by the turtle, but the turtle does not experience any significant impact from their presence. This distinguishes commensalism from mutualism, where both species benefit, and parasitism, where one organism benefits at the expense of another. It is also different from predation, where one organism hunts and consumes another for sustenance. Understanding the nuances of these relationships is key in the study of ecology and symbiotic interactions.