Encryption Data in Transit and at Rest

1. For creating a file system with encryption enables.

2. When mounting the file to the instance

Encryption done over a tunnel. You are mounting locally againt the local host and the mount helpers is setting up and maintinaing the tunnel so that's why the output of th mounts in DF command will shown localhost because of that

EFS - is file system

S3 - Object store

EBS - Block store