The judiciary primarily adjudicates civil, criminal, and arbitration cases. Most systems have a hierarchical court structure, while some countries adhere to sharia law. The English common law tradition influences case law in the US. US law comes from constitutions, statutes, regulations, and precedent-setting cases. Key Supreme Court decisions established judicial review and expanded civil rights. The Warren, Burger, and Rehnquist Courts shifted the scope of individual liberties and criminal justice over time. The federal court system includes district, appeals, and Supreme Courts, which decide cases through written arguments and rulings that can be unanimous or include dissents. Judges are nominated by the president and approved by the Senate.