In what scenario would you use AWS Elastic File System (EFS)?

AWS Elastic File System (EFS) is designed specifically for scenarios where there is a need for scalable network file storage that can be concurrently accessed by multiple instances. It supports the NFS (Network File System) protocol, making it ideal for applications that require shared file access among several EC2 instances. This feature allows multiple instances to read from and write to the same files in a seamless manner, providing a centralized storage solution that can be easily scaled as needed.

When considering the needs for temporary storage of logs, hosting static websites, or managing database backups, other AWS services would be more appropriate. Temporary storage of logs may be better suited for services like Amazon S3 or AWS CloudWatch, where data can be effectively managed and accessed without needing a file system interface. Hosting static websites is typically done using Amazon S3 due to its high availability and low latency for serving static content, while database backups would usually be directed to services like Amazon RDS snapshots or S3, which offer more suitable options for backup and recovery functionalities. Thus, the scenario of sharing file data between EC2 instances is where EFS excels.