A deposition is a tool used primarily in civil lawsuits for uncovering evidence before an actual trial. In theory and in fact, depositions help resolve cases before trial because each person involved in the case can learn the facts from his or her opponent and from independent witnesses.
Depositions usually take place in a conference room in the office of one of the lawyers involved in the case. One or more lawyers for each party to the lawsuit is present. The parties to the lawsuit are often present, but need not be present unless they are going to testify.
The deposition itself is sworn testimony. The person giving the testimony is called the "deponent." The deponent is asked questions by the lawyers for the parties in the case. The questions and the answers to those questions are recorded by a court reporter and, sometimes, also recorded on video. The deponent has a right to have his or her lawyer present.
The testimony given at a deposition can be used at trial in several different ways. Generally, the mere fact that a deposition has been given by a party to the case or a witness does not excuse the party or witness from actually appearing at trial and giving live testimony, although there are several exceptions to that rule.
A lawyer will prepare his or her client for the deposition. A lawyer may also prepare a witness for a deposition. With appropriate preparation, a deposition is usually not a stressful event. Most lawyers are very courteous to the deponent.