What term describes the relationship between a parasite and its host?

The term that accurately describes the relationship between a parasite and its host is parasitism. In this type of relationship, the parasite benefits from the interaction at the host's expense, often causing harm or detriment to the host. The parasite relies on the host for nutrients or habitat, which can lead to various negative effects on the host's health or wellbeing.

Other terms, such as mutualism, commensalism, and symbiosis, represent different types of relationships. Mutualism involves both parties benefiting from the interaction, while commensalism benefits one party without affecting the other. Symbiosis is a broader term that encompasses various types of close ecological relationships, including all the aforementioned types. However, parasitism specifically highlights the negative impact on the host, making it the correct term for this relationship.