Amazon S3 Glacier is specifically optimized for data archiving, providing secure and durable storage for data that is rarely accessed. It is a cost-effective solution for long-term data retention, such as for regulatory compliance, because it offers lower storage costs compared to other storage classes intended for more frequent access. Amazon S3 Standard is designed for general-purpose storage of frequently accessed data. Amazon S3 Intelligent-Tiering is designed to optimize costs by automatically moving data between access tiers based on changing access patterns. Amazon S3 One Zone-IA provides low-cost storage for infrequently accessed data, but unlike Amazon S3 Glacier, it does not target long-term archival storage needs and retains data in only one Availability Zone.