Affidavit

A written statement made voluntarily by an individual, known as the affiant, who swears or affirms under oath or affirmation before a person authorized to administer oaths, such as a notary public or commissioner for oaths, that the information contained within the document is true to the best of their knowledge. 

It serves as a formal, sworn declaration of facts and is used as evidence in legal proceedings, particularly when a witness cannot appear in person or when a party needs to present written testimony. The document typically includes a preamble identifying the affiant, the statement itself, and a jurat at the end certifying the oath was administered on a specific date and place. Because it is made under penalty of perjury, providing false information in an affidavit can result in serious legal consequences, including prosecution for perjury.