Individuals dissatisfied with the decision of a civil or criminal trial have recourse – the Appellate Court. The United States Constitution, as well as individual state constitutions, guarantee the right to appeal. Appellate law, then, deals with judgments that can be appealed and what procedures must be followed to bring appeals before the court, including the filing and challenging of various writs and other issues. 
Appellate courts review the evidence and happenings that occurred in trial court; they do not seek out or review evidence that was not presented in the initial trial. It is the job of the Appellate Court, however, to decide if the procedures that were followed at trial were correct and if the appropriate law was utilized during the trial.
Appeals can be filed after a judgment from a trial court or after a pretrial dismissal. In the first instance, the Appellate Court can decide to overrule the trial court’s final decision if the Appellate Court finds legal errors were committed and that those errors adversely affected the outcome. Those errors could include such things as wrongly excluding or admitting evidence, giving the jury incorrect instructions, or not properly following procedures.
