These words may all denote statements made to a court of law. Testimony is any declaration made by a witness who is considered to know the facts of a case. Giving testimony involves the taking of an oath and the making of statements in open court in answer to questions put by a lawyer or qualified public official. Testimony in its wider meaning is affirmation or proof of something: The ruined buildings of the city bear grim testimony to the heavy bombardment by the enemy.

Both affidavit and deposition are types of legal testimony put into writing. Although occasionally used interchangeably, affidavit and deposition differ in several ways. An affidavit is a sworn document made voluntarily without cross-examination. Also, an affidavit may be accepted a testimony by a court when the testifier is unable to appear in person. A deposition , on the other hand, is made orally under oath in response to formal questioning, and is taken down in writing. Unlike an affidavit , a deposition is subject to cross-examination.

Evidence is the most general term, and it includes the testimony of witnesses , affidavits , depositions and all the facts and physical objects connected with a legal proceeding. In everyday use, evidence is anything that tends to prove a thing true.

• Scholars have been able to unearth some evidence as to the true authorship of the book; Her red eyes and sad expression were evidence (and also testimony to the fact) that she had been crying.