A random identifier or text fingerprint
UUID v4 is generated with Web Crypto and can identify application records. SHA-256 creates a deterministic fingerprint of UTF-8 bytes; changing a character or space changes it.
Example and limitations
Hashing does not encrypt text or securely store weak passwords. Password storage requires a purpose-built password hashing method with a salt; plain SHA-256 is insufficient.
Is a UUID an access secret?
No. An identifier does not replace authentication or an access key.