Definition
NAT, or Network Address Translation, is a method used to remap an 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. It essentially allows multiple devices on a private network to share a single public IP address when connecting to the internet. NAT works by altering the source IP address and port number of outgoing packets and then reversing the process for incoming packets, using a translation table to keep track of connections. This is crucial for conserving public IP addresses and adding a layer of security by hiding internal network structures. For instance, a home router uses NAT to give all your connected devices internet access using only your ISP assigned IP. It is often confused with port forwarding, which is a specific type of NAT configuration. You will encounter NAT concepts on CompTIA Security+, Network+, CySA+, and AWS Certified Solutions Architect Associate exams.