As the name indicates, a gateway endpoint is a gateway. This gateway enables the instances within the VPC to connect to some AWS services. The AWS services that can currently be accessed using a gateway endpoint are S3 and DynamoDB.

S3 and DynamoDB have an internet end point. Before the gateway was introduced, the only ways to reach S3 or DynamoDB from inside a VPC was to either leverage the internet gateway if the instance was in the public subnet, or through a NAT gateway if the instance was in a private subnet. With the introduction of the gateway endpoint, instances inside a VPC can reach S3 and DynamoDB using the gateway endpoint. There is no need for an internet gateway or an NAT Gateway to access S3 and DynamoDB from within a non-default VPC.

To use the gateway endpoint, the user needs to update the routing table and point to the gateway endpoint as the target for routes to S3 and DynamoDB.