NAT network address translation is a process of mapping an IP address or IP port pair to another IP address or IP: port. You might be wondering what a software engineer like me doing making a video on a low level networking concept? I have good reasons for that. NAT was originally designed to solve the ipv4 limited IP addresses, but since been used for port forwarding and layer 4 load balancing through the virtual ip address such as Haproxy thats why I decided to make a video about NAT from a software engineer view. In this video we will explain how NAT works and we will explain its applications.