A summation is a final review or conclusion, often given in a court of law. As the incompetent lawyer approached the bench for the final time, he told the judge and jury, "In summation, my client is guilty of all charges."
At the end of every court case, both the defense and prosecution give a summation — a quick rundown of all the facts from the case to help the jury decide on a verdict. When used outside of the courtroom, summation simply means recounting a group of items or events. At the end of a father-son camping trip, the son gives his mother a summation of the trip. You'll note that summation begins with the prefix sum-, meaning "to add up." In fact, another definition for summation is the process of adding things together, or the final sum.