S3 is short for Simple Storage Service, and Amazon S3 is the most supported storage platform available.

S3 is object storage that can store and retrieve any amount of data from anywhere.

Despite that versatility, it is practically unlimited as well as cost-effective because it is storage available on demand.

In addition to these benefits, it offers unprecedented levels of durability and availability.

Amazon S3 helps to manage data for cost optimization, access control, and compliance.

https://docs.aws.amazon.com/AmazonS3/latest/userguide/Welcome.html

AWS Simple Storage Service or S3 for short is one of AWS's core services. It allows users to store objects in the cloud and can be used for a large range of things from hosting static website to large scale data lakes.

S3 can hold virutally an unlimited amount of data and is a cost effective storage solution.

You are able to connect to S3 via the CLI, SDK or the console. At default the public is unable to access S3 but this can be charged using resource policy, IAM policies and ACL configurations.