What is the difference between S3 and EBS in AWS

Short answer

S3 is scalable object storage accessed over HTTP, ideal for files, backups, and static assets. EBS is block storage attached to a single EC2 instance, designed for databases and applications needing a POSIX filesystem.

Details

S3 offers 99.999999999% durability, virtually unlimited storage, and features like versioning, lifecycle policies, and event notifications. It is eventually consistent for overwrite PUTs and DELETEs (read-after-write for new objects). EBS provides low-latency block devices with snapshot backup to S3. An EBS volume is tied to an Availability Zone, while S3 buckets are regional.

For serving static websites directly from S3, see How to configure CloudFront CDN for static websites to add caching and HTTPS at the edge. If you are containerizing an app that writes to disk, how to use Docker volumes explains persistent storage concepts analogous to EBS.

Tips

• Use S3 for any data shared across multiple instances or services.
• Choose gp3 EBS volumes for a balance of price and performance; use io2 Block Express for the most demanding databases.
• Implement S3 bucket policies and encryption to meet security requirements.