There are two types of trials: trials decided by a judge, called bench trials, and trials decided by a jury, a select group of peers.
In a bench trial, a judge hears the testimony and evidence and decides if the facts of the case have or have not been proven. In the United States, traffic courts and juvenile courts are commonly decided by judges.
In a jury trial, a group of six to twelve adults chosen randomly from the community is presented with testimony and evidence from lawyers representing the plaintiff and the defendant in the case. Once both sides have presented, jurors gather to try to reach a verdict. Criminal trials in the U.S. are usually tried by jury.