Which feature of VPC Endpoints allows access to AWS services without data transfer costs?

The feature of VPC Endpoints that allows access to AWS services without data transfer costs is private connectivity. When using a VPC Endpoint, data is routed directly within the Amazon network instead of traversing the public Internet. This means that data transfers to supported AWS services through the VPC Endpoint do not incur additional data transfer costs, as they are treated as internal traffic to the AWS network.

Private connectivity ensures that communication between your VPC and the AWS service happens within the AWS backbone network, thus providing benefits such as reduced latency, enhanced security, and no transit charges related to data movement. Moreover, since the traffic remains within the AWS infrastructure, customer data is less exposed to potential threats associated with public Internet pathways.

In contrast, options like public accessibility and direct connection do not correlate with the elimination of transfer costs. Public accessibility refers to whether an endpoint is reachable from the Internet, while direct connection typically relates to AWS Direct Connect, which has its own cost structure separate from the use of VPC Endpoints. Increased security is certainly a benefit of using VPC Endpoints by limiting exposure, but it does not directly impact data transfer costs. Therefore, private connectivity is key to understanding how VPC Endpoints can prevent data transfer charges when accessing AWS services