AWS EFS vs EBS vs S3 (differences & when to use?)

Question

As per the title of this question, what are the practical differences between AWS EFS, EBS and S3?

My understanding of each:

• S3 is a storage facility a

Answer 1

I wonder why people are not highlighting the MOST compelling reason in favor of EFS. EFS can be mounted on more than one EC2 instance at the same time, enabling access to files on EFS at the same time.

(Edit 2020 May, EBS supports mounting to multiple EC2 at same time now as well, see: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-volumes-multi.html)