united-states
What are the circuits of law?
<p>I hear all the time that something is in the 5th circuit or the 1st circuit of [INSERT STATE HERE]. </p>

<ul>
<li>What exactly are the different circuits? </li>
<li>How is law applicable based on the circuit?</li>
</ul>

<p>A "circuit court" is a kind of court in a judicial system. It generally covers a large-ish area; the name comes from the fact that back in the days of horseback travel, judges would literally ride around a circuit to hold court. The exact meaning depends on the court system.</p>

<p>At the federal level, the circuit courts are the main federal appeals courts. Each one covers multiple states (except the DC Circuit which just covers DC and the Federal Circuit which has subject-based jurisdiction). A circuit court normally hears cases before a 3-judge panel; that panel's decision is normally binding precedent in federal courts throughout the circuit, including on future panels of the same circuit. Panel decisions can be overturned by SCOTUS or by the circuit court sitting <em>en banc</em> (i.e. all the judges hear the case, not just 3 of them). Outside the circuit, a circuit court's decision is only persuasive precedent.</p>

<p>At the state level, what circuit courts do depends on the state. In many states that have them, they're the most important trial courts, handling large civil cases and felony criminal cases. Some states have lower-tier courts to handle minor issues, in which case they might allow an appeal from the lower courts to the circuit court. This appeal might be like a normal appeal (where the higher court looks at the record from the lower court and only considers whether the lower court got the law wrong), or might be a trial <em>de novo</em> (where the higher court throws out the lower court's decision entirely and tries the case itself from scratch). It really depends on the state. If a state's circuit courts are trial courts, they generally don't set much of a precedent.</p>
