Which component is used to uniquely identify an object in a cloud object storage like S3?

• A. GUID
• B. directory
• C. block size
• D. metadata

Answer: (A)

In cloud object storage, every object must have a unique, stable identifier so the system can locate and reference it without ambiguity. A GUID (globally unique identifier) serves this purpose as a standardized, collision-free ID that the storage system can use internally to track the object. While you typically interact with objects via a bucket and a key (name/path), the internal identifier that ensures uniqueness across the system is a GUID.

Directories aren’t part of object storage’s flat namespace, so they don’t serve as unique identifiers. Block size relates to how data is chunked or stored at a lower level and isn’t used to identify objects. Metadata describes attributes of the object but doesn’t uniquely identify it on its own. Therefore, the GUID is the component that provides a unique identifier for the object.