What kind of storage classes have you used?

S3 offers several storage classes that balance cost and access frequency. The most common are Standard (for frequent access), Standard‑IA (infrequent access with lower storage cost but higher retrieval cost), One‑Zone‑IA (infrequent access in a single AZ), Intelligent‑Tiering (automatic tiering between frequent and infrequent tiers), Glacier (low‑cost archival with retrieval times of minutes to hours), and Glacier Deep Archive (lowest cost, retrieval up to 12 hours). I have used Standard for active data, Standard‑IA for logs that are accessed a few times a month, and Glacier for long‑term backups. I also leveraged Intelligent‑Tiering for data with unpredictable access patterns. Choosing the right class depends on access patterns, durability needs, and cost constraints.