What kind of relationship do parasites typically have with their hosts?

Parasites typically have a parasitic relationship with their hosts, which is characterized by one organism benefiting at the expense of the other. In this dynamic, the parasite derives nutrients, shelter, or other benefits from the host while potentially causing harm to it, such as illness or reduced fitness. This relationship is inherently exploitative, as the parasite relies on the host for its survival and reproduction.

While some relationships may be classified as commensal, mutualistic, or symbiotic, these do not accurately describe the nature of the interaction between parasites and hosts. Commensal relationships involve one party benefiting while the other is neither helped nor harmed; mutualistic relationships involve both parties benefiting; and symbiotic relationships can include various forms of interaction, but not all symbiotic relationships result in a disadvantage for one party, which distinguishes them from parasitic relationships. Therefore, identifying the relationship as parasitic is crucial to understanding the dynamics of host-parasite interactions in parasitology.