Storage volumes you can attach to your EC2 instances - essentially a virtual hard disk. Need a minimum of 1 volume per EC2 instance, this is called the root device volume.
Useful for file systems, databases, OS, data, etc. Designed for mission critical data. Highly available, and scalable.
EBS volumes will always be in the same AZ as EC2, this has obvious benefits such as latency.
You can resize the volumes on the size, i.e. the instance does not to be stopped. However you will need to extend the filesystem in the OS so the OS can see the resized volume.
You can also switch volume types on the fly.
Volumes exist on EBS, snapshots exist on S3.
Different types of EBS volumes, based on price/performance.
Also see EFS and FSx: [[20211220030433-aws-efs]] [[20211220030623-aws-fsx]]