A host in the context of research refers to an organism that harbors or supports another organism or entity. In the field of microbiology, a host can refer to a plant, human, animal, or other organism that provides a habitat for pathogens such as bacteria, viruses, or parasites. Understanding the relationship between hosts and pathogens is crucial in studying infectious diseases and developing treatments or prevention strategies. Researchers might study factors that influence a host's susceptibility to pathogens, how pathogens interact with host cells, and how the host's immune system responds to infection. The study of hosts in research can also extend to other areas such as symbiotic relationships between organisms or the impact of environmental factors on host health.