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