Give a few usage scenarios for S3.

Build an infrastructure that hosts videos, photos, or music uploads files to this storage and then clients can download from this storage. All of that can happen from a private network or via the internet.

S3 provides data backup and storage for other services in AWS, such as EBS snapshots and Amazon Machine Image templates. EBS is a block storage option offered by AWS. Basically, these are virtual hard drives you can attach to EC2 machines. Point-in-time backups can be taken from these EBS volumes. These backups are called snapshots and these snapshots are saved into AWS S3 by default.

Hosting static websites consisting of markups and client-side script, this restricts storing PHP, ASP, or any other dynamic website on S3 storage but it provides an automatically- scalable, cheap, and reliable website hosting service, and this static content can work with the dynamic backend, which can be hosted in AWS Lambda or any other backend service.

Hosting software application installers that clients can download. For example, your company is producing an image editor for Windows. The MSI installer files can be saved into S3 storage, and then you can provide your clients with the URL to this storage object. The clients can go ahead and download and install this MSI from S3.