Courts are state and federal government institutions with the authority to decide legal disputes and administer justice under the law in civil, criminal, and administrative matters. Courts are generally given this authority under the relevant state or federal constitution, and the relevant state or federal statutes. Courts are generally staffed by (1) one judge (in trial courts) or a panel of judges (in appellate courts) who interpret and apply the law; (2) support staff members that may include administrators (clerks); (3) a court reporter to record court proceedings; and (4) a bailiff to provide security.

The room in which court proceedings are conducted is known as the courtroom, and the building that includes the courtroom is known as the courthouse. The term “the court” may be used to refer to the judge or judges who are presiding over court proceedings. The judges in a state or federal court system are collectively known as the judiciary.

In Illinois, courts operate at both the state and federal levels to resolve legal disputes and uphold justice in civil, criminal, and administrative cases. The authority of these courts is derived from the Illinois Constitution and state statutes, as well as the U.S. Constitution and federal laws for federal courts. Illinois state courts are organized into circuits, with each circuit having its own trial courts. These courts are typically presided over by a single judge, while appellate courts have panels of judges. The Illinois Supreme Court is the highest court in the state. Federal courts in Illinois, such as the U.S. District Courts and the Seventh Circuit Court of Appeals, follow a similar structure but operate under federal law. Courtrooms, located within courthouses, are where legal proceedings take place, and the term 'the court' can refer to the presiding judge or judges. Judges, supported by clerks, court reporters, and bailiffs, form the judiciary and are responsible for interpreting and applying the law.