(Internet) Acronym of network address translation. A network function whereby one network address is rewritten (translated) to another address: Network Address Translation is frequently used to allow multiple network nodes (computers or inter-networked devices) to share a single internet (or local network) IP address. NAT may be used in "one to one", "many to one", or "one to many" types of configurations.
(Internet) Acronym of network address translator. A device that implements that network function; a NAT firewall.