Deletes the specified snapshot.
When you make periodic snapshots of a volume, the snapshots are incremental, and only the blocks on the device that have changed since your last snapshot are saved in the new snapshot. When you delete a snapshot, only the data not needed for any other snapshot is removed. So regardless of which prior snapshots have been deleted, all active snapshots will have access to all the information needed to restore the volume.
You cannot delete a snapshot of the root device of an EBS volume used by a registered AMI. You must first de-register the AMI before you can delete the snapshot.
For more information, see Deleting an Amazon EBS Snapshot (http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-deleting-snapshot.html) in the Amazon Elastic Compute Cloud User Guide.