The two levels
An object store has just two naming levels. A bucket is a top level container that holds objects and carries ownership, region, and access policy. A key is the full string name of one object inside a bucket. Together a bucket and key uniquely locate an object.
Keys are flat
A key like reports slash 2026 slash q1 dot pdf contains slashes, but there is no real folder. The slash is just a character in a flat string. A listing with a prefix plus a delimiter simulates folders by grouping keys that share a common start.
Why buckets matter
- They are the unit of access control and billing.
- They pin a region so data location is predictable.
- Their names are often globally unique so they can map to a stable address.
Key idea
Buckets carry ownership and policy while keys are flat strings whose slashes only imitate folders through prefix listing.