Amazon S3 allows us to store data in the form of objects inside the bucket. It stores objects in key-value form, where the object is assigned with a unique key and the value is the object. S3 doesn't restrict to store the amount of data on the bucket. The size of the objects can be up to 5 terabytes. Each object is assigned a URL, which can be accessed via the HTTP or HTTPS protocol. We can manage the access control list at the object level also.

Amazon S3 stores objects in a flat structure. It doesn't have any hierarchical structure where we can group objects under the bucket. But Amazon S3 Management Console provides support for displaying objects under folders and nested subfolders. Amazon Management Console distinguishes the folders with / in the object's key name. For example, if we provide the object key as PACKT/chapter4.txt, then it will show PACKT as the folder and below that chapter4.txt as the object.

Each S3 object contains the following: