host

Host is a term with multiple related meanings. In social contexts, a host is a person who entertains guests and organizes events. The word can also refer to a person who accommodates travelers or serves as a venue.

In biology and medicine, a host is an organism that harbors another organism, such as a parasite, symbiont, or pathogen. The host typically provides nourishment and habitat, while the parasite benefits. Host-parasite relationships can be specific to certain species; some life cycles require alternate hosts.

In computing and networking, a host is any device connected to a network that can send and receive data. A host runs software services, is identified by a host name and IP address, and may host websites, databases, or applications. The term also appears in virtualization and cloud contexts as the physical or virtual machine on which guest systems run.

Other uses include entertainment contexts where a host presents programs or segments, and ecology concepts such as reservoir hosts that harbor pathogens and play roles in transmission.