For an injury lawsuit, a legal deposition is a formal process where the injured person testifies under oath. This usually means one of the parties (either the injured person's attorney or the defense or insurance attorney), assures that a licensed court reporter/stenographer is present to record the injured person's testimony, which then can be used in certain ways in the injury case.
Every state and federal court specifies a written court procedure on exactly how a deposition can be conducted, and other provisions specify how it can later be used once it is typed up by a court reporter.
Also, these written court rules specify that such a deposition can be videotaped and some court rules even provide that a deposition may in fact be videotaped and without a court stenographer present. Court reporters are highly trained and most states require licensure.