Comprehensive and Detailed 100to 150 words of Explanation From AWS Certified Security – Specialty topics:

AWS Backup uses backup plans to define backup frequency, lifecycle behavior, cold storage transition, and retention. For snapshot-based backups, AWS Backup supports retention periods from 1 day up to 100 years, or indefinitely if no retention is specified. Therefore, a backup plan with a 5-year retention period is the correct lifecycle-management mechanism. Tags alone do not enforce retention. The customer does not directly manage an S3 bucket that AWS Backup uses for RDS snapshots, so S3 versioning or S3 Lifecycle policies are not the correct control path. RDS native automated backups have shorter retention limits, but AWS Backup snapshot retention is managed through the AWS Backup plan and is the appropriate service-level mechanism for long-term retention.

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