Network Interface Permission in AWS is a security feature that allows an administrator to define and manage network access for resources within the AWS environment. By leveraging Network Interface Permission, administrators can control who has access to specific parts of the AWS environment, ensuring only authorized users are able to connect and utilize resources. This security feature is useful for protecting sensitive data and resources from unauthorized access, as well as preventing malicious actors from gaining access to potentially vulnerable parts of the system. Network Interface Permission works by granting or denying permission on a per-interface basis; this means that all traffic passing through an interface must meet the criteria set by the administrator before it is allowed into or out of the system. Additionally, Network Interface Permissions can be configured using IAM policies, which allow administrators greater flexibility when defining their network security rules.