Network Address Translation (NAT)
Network address translation rewrites the IP addresses in packets as they pass through a router, typically letting many devices with private addresses share one public address.
What is Network Address Translation (NAT)?
Home routers use NAT so that all devices, given private addresses from the RFC 1918 ranges (10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16), appear on the internet under one public IPv4 address. Operators use carrier-grade NAT to stretch scarce IPv4 addresses. NAT is much less needed with IPv6.