With the authentication of a signature, the notary certifies that it belonged to a specific person, either because the signature was stamped in the notary’s presence, or because the notary was already familiar with it, or because it matched with an existing signature which had been previously authenticated or was unquestionably submitted in accordance with the law.

The purpose of a testimony is to certify, through the corresponding notarial statement, that a given photocopy is an exact replica of the original document.