Short for Network Address Translation, an Internet standard that enables a local-area network to use one set of IP addresses for internal traffic and a second set of addresses for external traffic. A NAT box(such as a router) located where the LAN meets the Internet makes all necessary IP address translations.
NAT
Meaning of NAT in English
DAX English glossary of key connectivity terms. Английский глоссарий основных терминов по коммуникациям DAX. 2012