Verifier
A verifier is the party that checks a presented credential: validating the issuer's signature, confirming the credential has not been revoked, and reading only the claims the holder chose to disclose.
A verifier is often the same organisation as the relying party requesting the credential, but the roles are distinct: the relying party decides what to ask for and what to do with the result, while the verifier is the technical function that checks the signature, the Trusted List entry of the issuer, and the revocation status before that result can be trusted.