Jury

A jury is a sworn body of people convened to render an impartial verdict (a finding of fact on a question) officially submitted to them by a court, or to set a penalty or judgment. Modern juries tend to be found in courts to ascertain the guilt, or lack thereof, in a crime. In Anglophone jurisdictions, the verdict may be guilty or not guilty (not proven; a verdict of acquittal, based on the state's failure to prove guilt rather than any proof of innocence, is also available in Scotland). The old institution of grand juries still exists in some places, particularly the United States, to investigate whether enough evidence of a crime exists to bring someone to trial.

The modern criminal court jury arrangement has evolved out of the medieval juries in England. Members were supposed to inform themselves of crimes and then of the details of the crimes. Their function was therefore closer to that of a grand jury than that of a jury in a trial.

The word jury derives from Anglo-Norman juré ("sworn"). Juries are most common in common law adversarial-system jurisdictions. In the modern system, juries act as triers of fact, while judges act as triers of law (but see nullification). A trial without a jury (in which both questions of fact and questions of law are decided by a judge) is known as a bench trial.

The "petit jury" (or "trial jury", sometimes "petty jury") hears the evidence in a trial as presented by both the plaintiff (petitioner) and the defendant (respondent). After hearing the evidence and often jury instructions from the judge, the group retires for deliberation, to consider a verdict. The majority required for a verdict varies. In some cases it must be unanimous, while in other jurisdictions it may be a majority or supermajority. A jury that is unable to come to a verdict is referred to as a hung jury. The size of the jury varies; in criminal cases involving serious felonies there are usually 12 jurors.

...
Wikipedia