Deposition
During a deposition, a party or witness' out-of-court testimony is taken. For example, an expert witness is deposed to determine what his opinions are. The deponent is asked questions by attorneys representing the parties in the case. Testimony is given under oath. Deposition testimony is usually recorded by a court reporter.
The transcript of the deposition can then be used throughout the case. For example, during trial, an attorney who is questioning a witness may use that witness's deposition testimony to point out inconsistencies in the witness' trial testimony.