Introduction Simple Storage Service (S3) is AWS’ binary large object (blob) storage system, capable of storing an unlimited number of files (up to 5TB in size per file) in a highly durable, dependable, and secure manner. This allows S3 to serve a multitude of use cases, such as publicly accessible static website assets, private data lake files, service logs, system backups, and many others. Each of these uses will require different permission levels and controls.