An affiant is a person who makes and signs an affidavit. He recites certain facts that are, or might be in the future, relevant to some legal matter. He generally types, or has someone type, the facts into a document, then signs it before a public official, generally a notary public or county clerk, raising his hand and swearing to the official that the facts in the affidavit are true. This act of swearing makes the affiant liable to criminal prosecution for perjury, a felony, if he has intentionally or recklessly lied about the facts. An affidavit is a formal sworn statement of fact, written down, signed, and witnessed (as to the veracity of the signature) by a taker of oaths, such as a notary public. ... An Embossed Notary Seal A notary public is an officer who can administer oaths and statutory declarations, witness and authenticate documents and perform certain other acts varying from jurisdiction to jurisdiction. ... The term county clerk has been commonly applied, in several English-speaking countries, to an influential employee of a county administration. ... Perjury is lying or making verifiably false statements under oath or affirmation in a court of law or in any of various sworn statements in writing. ... A felony, in many common law legal systems, is the term for a very serious crime; misdemeanors are considered to be less serious. ...

In many jurisdictions a person can make the legal equivalent of affidavit by simply reciting that the facts in the document are made under penalty of perjury. Such a document is called a "sworn declaration" or "sworn statement" and differs from an affidavit only because it is not witnessed and signed by an official. The person making and signing a sworn declaration is called a sworn declarant (or sometimes, informally, simply a "declarant") rather than an affiant. In law, jurisdiction from the Latin jus, juris meaning law and dicere meaning to speak, is the practical authority granted to a formally constituted body or to a person to deal with and make pronouncements on legal matters and, by implication, to administer justice within a defined area of responsibility. ...