Habitat - The specific geographical area or physical environment that is inhabited by an organism or a population of organisms.⏎
Host - An organism that harbors a parasite or another organism where there is a symbiotic relationship between the two organisms. In some cases, the relationship is commensal, or mutually beneficial, but in the case of a parasite and host, the host may be hurt by the parasite's presence.⏎
Microbe - Sometimes referred to as a microorganism, a microbe is an organism that is microscopic and thus invisible to the naked eye. ⏎
Immune System - The system of biological structures and processes that protects the body from foreign substances, including pathogens.⏎
Infection - The entry, establishment, and replication of pathogens inside a host organism.⏎