An appellate court is a court that hears appeals from decisions of lower courts or tribunals, rather than trying cases from scratch or hearing new evidence. In practice, it reviews alleged errors of law, procedure or, more rarely, findings of fact, and may uphold, vary, set aside or order a retrial of the decision under appeal.Across the UK and Ireland, “appellate court” is a descriptive term rather than a single defined statutory concept. Key appellate courts include the Court of Appeal (England and Wales, and Northern Ireland), the Sheriff Appeal Court and Court of Session (Inner House) in Scotland, and the Court of Appeal in Ireland. The UK Supreme Court and the Supreme Court of Ireland function as final appellate courts in most civil and many criminal matters.Appeals are governed by specific procedural rules (for example, the Civil Procedure Rules, Criminal Procedure Rules, Act of Sederunt or Irish court rules) and almost always require permission to appeal. For practitioners, understanding appellate jurisdiction, standard of review, time limits and remedies is critical for advising on appeal prospects, preserving points of law and formulating appropriate appellate advocacy.