Different Storage tiers in Amazon S3 are as follows:

1. S3 Standard: In this tier, S3 supports durable storage of files that

become immediately available. This is used for frequently used files.

2. S3 Standard -Infrequent Access (IA): In this tier, S3 provides

durable storage that is immediately available. But in this tier files are

infrequently accessed.

3. S3 Reduced Redundancy Storage (RRS): In this tier, S3 provides

the option to customers to store data at lower levels of redundancy. In

this case data is copied to multiple locations but not on as many

locations as standard S3.

https://aws.amazon.com/s3/storage-classes/