Democracy is not an easy form of government, because it is never final; it is a living, changing organism with a continuous shifting and adjusting of balance between individual freedom and general order.—Ilka Chase
America has a two-part court system: federal and state.
Both court systems follow similar procedures. In the U.S., a court does not decide what cases will be brought to it. Criminal cases begin when a prosecutor charges someone with a crime. Civil cases begin when a plaintiff brings a lawsuit against someone else (the defendant).
At the beginning of a trial, the judge and the jury are the last to enter the courtroom. The judge sits at the front of the room, higher than the rest of the court, and faces everyone.
The prosecuting attorney always sits at a table closest to the jury, facing the judge. The defense attorneys and their clients sit next to the prosecutor.
The prosecutor begins the trial with an opening statement. The defense attorney can also give an opening statement. The prosecutor presents evidence by calling witnesses, whom the defense can question after the prosecutor is finished. To ask questions of the other side's witnesses is to "cross-examine" them. The defendant has a choice whether to testify and whether to call witnesses. If the defendant or other defense witnesses testify, the prosecutor may cross-examine them.
At the end of the trial, in a closing statement, the prosecutor has one last chance to convince the jury the defendant is guilty. The defense follows with its closing statement to convince the jury the client is not guilty. The attorneys rest while the judge informs the jury about legal rules and the duty jury members must perform. In a criminal case, the jury must reach its verdict unanimously.