Definition
EFS, or Amazon Elastic File System, is a fully managed cloud file system service provided by AWS. It offers a simple, scalable, and elastic file storage solution that can be accessed concurrently by thousands of EC2 instances. EFS automatically scales its storage capacity up or down as files are added or removed, eliminating the need for provisioning or managing storage capacity. This service is crucial for workloads requiring shared access to data, such as web serving, content management, and big data analytics. For instance, a web application deployed across multiple EC2 instances can use EFS to store and access shared user uploaded content. Unlike EBS volumes, which are tied to a single EC2 instance, EFS provides a network file system accessible from many instances simultaneously. EFS is a key component in AWS certification exams like the AWS Certified Solutions Architect Associate and is often covered in cloud security certifications such as CCSP.