A notary is a person authorised to perform acts in legal affairs, in particular witnessing signatures on documents. The form that the notarial profession takes varies with local legal systems.
Documents are notarized to deter fraud and to ensure they are properly executed. An impartial witness (the notary) identifies signers to screen out impostors and to make sure they have entered into agreements knowingly and willingly. Loan documents including deeds, affidavits, contracts, powers of attorney are very common documents needing notarization.
Source: Wikipedia
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