What is the purpose of S3 Bucket?

A bucket is a container for objects stored in Amazon S3. Every object is contained in a single bucket, so the relationship between a bucket and objects is a one-to-many relationship. Many objects can be in one bucket, but one object cannot be in multiple buckets. Buckets identify the account responsible for storage and data transfer charges. Each bucket has an owner, and the account for the owner will be charged for the S3 storage costs. Access control rules can be applied to buckets. Also, buckets serve as the unit of aggregation for usage reporting which means detailed reports on the number of objects in a bucket can be obtained, the amount of transfer happening for the bucket, and etc. This information can be extremely useful for budgeting purposes.