Network Address Translation (NAT) is a method used in computer networking to modify the IP address information in packet headers while they are in transit across a router or firewall. This technique allows multiple devices on a local network to share a single public IP address, which helps conserve the limited number of available IP addresses. NAT operates by translating the private IP addresses of devices within a local network, such as those assigned by a router, into a public IP address that can be used on the Internet. This process enhances security by hiding internal IP addresses from external networks, making it more difficult for potential attackers to access devices directly.