u/AWS_CloudSeal

After working with a lot of AWS environments I still see engineers mixing these up regularly.

EBS vs EFS vs S3 they're not interchangeable.

EBS is a hard drive attached to one EC2 instance. Fast, low latency, lives and dies with that instance.

EFS is a shared network drive. Multiple instances can read and write simultaneously. Great for shared filesystems across containers or services.

S3 is object storage. Not a filesystem at all. Store files, retrieve them by URL. Infinitely scalable but not meant for live application reads.

The mistake I see most: teams use EBS when they need shared access across multiple instances and wonder why it doesn't work. Or they treat S3 like a filesystem and hit latency issues.