What does parasitism describe?

Parasitism describes a specific type of ecological relationship in which one species, the parasite, benefits at the expense of another species, the host. In this relationship, the parasite derives nutrients and resources from the host, which can lead to harm or even death for the host organism. This interaction is critical for understanding ecological dynamics and the impact of one organism on another within ecosystems.

In contrast to other ecological interactions such as mutualism—where both species benefit—and commensalism—where one benefits while the other is unaffected—parasitism specifically highlights the detrimental effect on the host. Understanding this relationship is important for topics such as disease ecology and the effects of invasive species.