NAT stands for Network Address Translation.

It is a method of remapping one IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic routing device.

In simpler terms, NAT allows devices on a private network to share a single public IP address when connecting to the internet. This is useful because there are not enough public IP addresses available to assign one to every device on the internet, but it also provides an additional layer of security by hiding the private IP addresses of devices on the network from the public internet.

NAT works by translating the private IP addresses of devices on a local network into a single public IP address that is visible on the internet. When a device on the private network sends a request to the internet, NAT changes the source IP address of the request to the public IP address of the router. When the response comes back from the internet, NAT changes the destination IP address of the response to the private IP address of the device that made the request.

This process allows devices on a private network to access the internet and communicate with devices on the internet while still maintaining a level of privacy and security.