What it is: A file stored in S3, plus metadata, stored under a key (path-like name).
What it’s for:
Store and retrieve files using the object key.
Attach metadata (content-type, tags, custom metadata).
Key ideas:
Object identity = bucket + key.
S3 is not a real “folder” system—folders are part of the key naming.
You can set permissions via ACLs (less preferred) or policies.
Exam cues:
Hard words:
*metadata* /ˈmetəˌdeɪtə/: siêu dữ liệu
*prefix* /ˈpriːfɪks/: tiền tố
*content-type* /ˈkɑːntent taɪp/: loại nội dung (MIME type)