The word Affidavit comes from a Latin word meaning for he has declared upon oath. It is essential to the validity of an affidavit that it be sworn to, or affirmed before, a notary public or some other officer authorized to administer oaths or affirmations. This may be done by having the officer administer the oath to the affiant or by having the affiant affirm to the officer, with the officer’s consent, the truth of the matters contained in the affidavit. It is also essential that the affiant be identified as to name, residence and, where appropriate or required by law, as to status or capacity. This is ordinarily done in the introductory paragraph to the affidavit. A person who makes an affidavit is called affiant.
An affidavit is based upon either the personal knowledge of the affiant or his or her information and belief. Statutes of various jurisdictions ordinarily prescribe various formal requirements for the affidavits. These requirements may be just proper form or may be essential as to the legal effect of the affidavit.