Affidavit v. Other Documents

An affidavit is a sworn document that is voluntarily produced without any cross-examination of the affiant.  An affidavit is different from a record of examination.  Depositions and in-court witness examinations allow for an opportunity for cross-examination; affidavits do not.  Additionally, depositions and in-court testimony can be compelled by subpeona; an affidavit is a voluntary statement.
An acknowledgment is a means of authenticating an instrument or document.  It is a declaration that the document was executed as an act by person whose name appears as the executor of the document.  An acknowledgment consists of an oral declaration of the party executing the instrument and a written certificate attesting to the oral declaration.  An acknowledgment does not constitute an “affidavit” because it does not purport to be a certification that the person acknowledging it swears to the truth of the matter set out.  A requirement that a paper be “sworn to” contemplates the execution of an affidavit that the facts contained in it are true, and not an acknowledgment.
The difference between an affidavit and an oath is that an affidavit consists of a statement of fact, which is sworn to as the truth, while an oath is a pledge.  A pleading is a request to a court to exercise its judicial power in favor of a party that contains allegations or conclusions of facts that are not necessarily verified.  Pleadings and affidavits are distinguishable in that affidavits must state facts under oath, whereas pleadings may contain allegations of ultimate facts, and verification of a pleading may not be necessary in all cases.

A certified copy is admissible as evidence in a lawsuit when the original document cannot be produced because it has been lost or destroyed.  A certified copy is a  photocopy of a document, judgment, or record that is signed and attested to as an accurate and a complete reproduction of the original document by a public official in whose custody the original has been placed for safekeeping.  A certified copy is considered as secondary evidence unless circumstances of loss or destruction warrant its treatment as primary evidence.  However, an unsupported affidavit with regard to material facts which may be dispositive of the matter at bar is not usually admissible as evidence.  Affidavits from persons who are dead or otherwise incapacitated, or who cannot be located or made to appear may be accepted by the court, but usually only in the presence of corroborating evidence.