What it is: Different cost/performance tiers for storing S3 objects.

What it’s for:

• Optimize cost based on access frequency and retrieval needs.

Common storage classes (exam-relevant):

• S3 Standard: frequent access.
• S3 Intelligent-Tiering: automatically moves objects between tiers.
• S3 Standard-IA: infrequent access (lower storage cost, retrieval fee).
• S3 One Zone-IA: infrequent access, stored in one AZ (lower durability vs multi-AZ).
• S3 Glacier / Glacier Deep Archive: archival storage.

Exam cues:

• “unknown access pattern” → Intelligent-Tiering.
• “infrequent access but must be available quickly” → Standard-IA.
• “long-term archive, lowest cost, can wait hours” → Glacier Deep Archive.

Hard words:

• *tier* /tɪr/: tầng/lớp
• *infrequent* /ɪnˈfriːkwənt/: không thường xuyên
• *retrieval* /rɪˈtriːvəl/: lấy dữ liệu ra
• *archival* /ɑːrˈkaɪvəl/: lưu trữ lâu dài (archive)