Here are the three storage classes that were available for Amazon EFS at that time:

Standard Storage Class:

This storage class is designed for general-purpose workloads where the emphasis is on balance between performance and cost.

It provides low-latency access to files and supports a wide range of use cases, including web serving, content management, and application development.

Standard storage is ideal for situations where you need a mix of read and write operations.

Infrequent Access Storage Class:

The Infrequent Access storage class is designed for files that are accessed less frequently but still require fast access when needed.

It offers a lower storage cost compared to the Standard storage class but with slightly higher latency for access.

This storage class is suitable for use cases where data is used intermittently, such as backups or disaster recovery.

One Zone Infrequent Access Storage Class:

This storage class is similar to the Infrequent Access storage class, but it's optimized for workloads that don't require high availability across multiple Availability Zones.

Data stored in the One Zone Infrequent Access storage class is confined to a single Availability Zone, which makes it a cost-effective option for applications that can tolerate potential data loss in case of an Availability Zone failure.

It's important to note that the availability of storage classes might vary based on the AWS region you are using. Additionally, AWS services and features can change over time, so I recommend referring to the official AWS Elastic File System documentation for the most current information on EFS storage classes and their features.