Glossary
Justice
The title used for judges who sit on a state supreme court or the U.S. Supreme Court. A justice does the same job as a judge but at the highest level of the court system.
Trial courts and intermediate appellate courts have judges. State supreme courts and the U.S. Supreme Court have justices. The work is similar: interpreting law, applying precedent, deciding appeals: but justices on the highest courts decide questions that affect everyone in their state (or the whole country, for the U.S. Supreme Court).
Some states use "justice" for trial-court judges too (New York is famous for this: its trial courts are called the Supreme Court, and its highest court is the Court of Appeals). Local terminology can be confusing.