NAT is a method of modifying an IP address by changing the information in the IP header. This enables several devices on a private network to use the same gateway to the internet.
Although the devices will share a similar public IP address, they will have unique private IP addresses. Most VPNs and WiFi routers offer these gateways. For instance, all the devices connected to the router will use the router’s public address, but each will have a different private IP address.
How do NAT works? The process isn’t as complicated as it seems. Essentially, when you access a web page, your device will direct a request to the router with a private IP address. Then, the router will change the request and send it to the site’s server using its public IP address. Finally, the server replies to the request, and the router sends it to your device through the private IP address.
On the other hand, a firewall is a protective layer that blocks unsolicited communications between devices. So, a NAT firewall permits only the traffic that has been requested by a device on the network to pass the gateway.
In fact, it discards malicious data packets or requests, effectively preventing potential dangerous connections. In addition, the firewall will mark any incoming traffic without a private network as unsolicited and destroy it.