A criminal case deals primarily with an individual versus society or the public. The individual in this case is accused of a violation of law. Original jurisdiction is the power to try a case. This power is given to trial courts. An appeal is a review of the law applied by the trial court.
Appeals are the responsibility of the appellate courts.
The court structure in Texas is composed of a number of different courts with overlapping areas of authority. The structure begins with local trial courts of limited jurisdiction. These courts have basically the same jurisdiction. On the civil side, they deal with small claims of a certain dollar amount. On the criminal side, they deal with traffic violations or pseudo crimes.