NAT (Network Address Translation) conserves legally registered IP addresses by privatizing intranets and using port-level multiplexing. With NAT overload (PAT), multiple internal hosts can share a single public IPv4 address for external communications, reducing the need for numerous external addresses. NAT enhances connection flexibility to public networks through features like multiple pools, backup pools, and load balancing, ensuring reliable connectivity. It also maintains consistency in internal network addressing, allowing organizations to change public IP schemes or ISPs without altering internal client configurations. While NAT hides internal IPv4 addresses (using RFC 1918 addresses), it is not a security measure; stateful firewalls provide network edge security.
