NAT (Network Address Translation) is a networking technique that allows devices on a private network to communicate with the internet using a single, shared public IP address. NAT works by mapping the private IP addresses of devices on the local network to a public IP address, allowing them to communicate with external servers and services.
There are several types of NAT, including static NAT, dynamic NAT, and port address translation (PAT). Static NAT involves mapping a specific private IP address to a specific public IP address, while dynamic NAT assigns available public IP addresses to private IP addresses on a first-come, first-served basis. PAT, also known as NAT overload, allows multiple devices to share a single public IP address by assigning them unique port numbers.
NAT is often used to conserve public IP addresses, as well as to provide a layer of security by hiding the private IP addresses of devices on the local network.