Depositions are important events in a personal injury case. A deposition has been explained (somewhat formally) as follows: A deposition is the sworn testimony of a witness taken before trial held out of court with no judge present. The witness is placed under oath to tell the truth and lawyers for each party may ask questions.
The questions and answers are recorded. The most important thing–besides telling the truth–at a deposition is to answer the question that is being asked.
It demonstrates to the defense attorney that you are alert, intelligent and will present well in front of a jury. It also prevents volunteering information (that may not be helpful to your case) that the defense attorney may not have thought to ask about.