An affidavit is a written statement. A person, known as the affiant, swears under oath to the statement's truthfulness.An affidavit is a written statement confirmed under oath, that is, the maker of the affidavit goes to see a person entitled to administer oaths. A sworn affidavit is a written statement made under oath, presenting facts and evidence without requiring verbal testimony. An Affidavit is a sworn statement which must be signed in front of a notary public. Knowledge of the person making the statement. In addition to submitting facts to the court, an affidavit is also used to submit documentary evidence and to "verify" other documents. A certification is a statement that certain facts are true to the best of the knowledge of the person making the statement. Affidavit of marriage : An affidavit of marriage is a sworn statement that two individuals are married. Oaths, Affirmations and Affidavits Taken Out of State. a.