S3 (Storage Bucket)

What is S3?
S3 stands for Simple Storage Service. It provides secure, durable, highly-scalable object storage. It means safe place to store your files. It is object-based storage. Files are stored in buckets (folders). Bucket names must be globally unique.


  • IAM permissions
  • Bucket policy on bucket
  • ACL(Access Control Lists) on objects
  • Public Access Settings at Account Level and Bucket Level
  • Pre-Signed URLs


Versioning is required for Cross-region replication.
Versioning delete marker.

Object Locking

  • Retention Periods : prevent updates or deletes for a given period of time.
  • Legal Holds : prevent updates or deletes until the Legal Hold is removed.
  • Versioning is required and through UI only during the bucket creation. Later by support ticket.
  • Cross-region replication is not supported with Object Locking enabled.
  • Cross-region replication is not supported when custom managed encryption is enabled on buckets.

S3 Encryption

Encryption can be applied both on buckets as default and at object level which overides the default.

S3 encryption types :

  • None
  • SSE-S3 (AES-256)
  • SSE-C (Customer Key)

S3 Performance

  1. Multipart Upload
  2. Transfer Acceleration
  3. Partitions and Object Naming. eg: bucket names should not start with current date or same name.