EFS

 Elastic file system

• managed NFS (network file system) that can be mounted on many EC2
• EFS works with EC2 instance in multi-AZ
• Highly available, scalable, expensibe (3x gp2), but we can pay only for the data we consumed(pay per use)
• EC2 instances can be connect to EFS over the security group configured for the EFS

• Use cases:content management, web sharing, data sharing, wordpress

More details. check on aws documentation