(1) An administrative unit defined in a DNS server. It may refer to a single domain name or a subdomain. See zone file, DNS records and DNS.

(2) A logical subnet in a Fibre Channel SAN network. Zones tie together groups of servers and storage devices for daily processing, but can be dynamically changed as required. For example, in order to enable periodic backups to storage devices outside the individual zones, the zones can be widened on the fly to reach them. See Fibre Channel.

(3) The term can be used for any subdivision of hardware and/or software.