Amazon S3 offers several storage classes:

1. S3 Standard: For frequently accessed data with low latency and high throughput.
2. S3 Intelligent-Tiering: Automatically moves data between two access tiers (frequent and infrequent) based on changing access patterns.
3. S3 Standard-IA (Infrequent Access): For data that is less frequently accessed but requires rapid access when needed.
4. S3 One Zone-IA: A lower-cost option for infrequently accessed data that doesn’t require multiple availability zone resilience.
5. S3 Glacier: For data archiving with retrieval times ranging from minutes to hours.
6. S3 Glacier Deep Archive: The lowest-cost storage for data that is rarely accessed and has retrieval times of hours.
7. S3 Reduced Redundancy Storage (RRS): For noncritical data where less redundancy is acceptable, although it is generally not recommended for new applications.

These classes allow users to optimize costs based on how often they access their data.