Things don’t always go the way you want them to. In New Zealand the High Court, Court of Appeal and Supreme Court all have jurisdiction to hear appeals from lower courts. The Court of Appeal and Supreme Court only hear appeals.
An appeal involves asking a judge or judges to review the decision of another judge, arguing that the decision was wrong and should be set aside or replaced.
I have successfully argued appeals against refusals to grant bail; pre-trial decisions; convictions and sentences.