To know about the VPC, Subnet, Internet gateway, Routing Table, then visit the previous article link is given below https://medium.com/@kunaljai844506/aws-vpc-by-terraform-32b361949575?source=friends_link&sk=47534f4eb1dedec8b917703371225187 Introduction What is NAT Gateway? It is a highly available AWS managed service that makes it easy to connect to the Internet from instances within a private subnet in an Amazon Virtual Private Cloud (Amazon VPC). Previously, you needed to launch a NAT instance to enable NAT for instances in a private subnet.