The federal judicial system is uniform throughout the United States and consists of three levels:
1a. District Courts
At the first level are the federal district courts, which are the 94 trial courts in the federal system. Every state has one or more federal districts; the less populous states have one, and the more populous states - California, Texas, and New York - have four.
The federal court with the heaviest commercial docket is the U.S. District Court for the Southern District of New York (Manhattan). The district judges throughout the United States commonly preside over all federal trials, both criminal and civil.
Federal judges - including Supreme Court justices - are nominated by the President and must be confirmed by the Senate. Unlike state judges, who are usually elected and preside for a fixed term of years, federal judges are appointed and sit for life unless they voluntarily retire or are impeached.
To assist the district courts, there are also 531 U.S. magistrate judges who serve under the district judge. These magistrates serve for set periods of time (not for life as judges and justices do), and they hear cases, issue search and arrest warrants, preside over misdemeanors or petty criminal trials, set bail, etc.
1b. Courts of Appeal
Cases from the district courts can then be appealed to the circuit courts of appeal, of which there are 13. Each circuit oversees the work of the district courts in several states.
The U.S. Court of Appeals for the Second Circuit hears appeals from district courts in New York, Connecticut, and Vermont.
The U.S. Court of Appeals for the Ninth Circuit hears appeals from district courts in California, Oregon, Nevada, Montana, Washington, Idaho, Arizona, Alaska, Hawaii, and Guam.
The U.S. Court of Appeals for the District of Columbia Circuit hears appeals from the district court in Washington, DC, as well as from numerous federal administrative agencies.
The U.S. Court of Appeals for the Federal Circuit, also located in Washington, DC., hears appeals in patent and customs cases.
Appeals are usually heard by three-judge panels, but sometimes there will be a rehearing at the court of appeals level, in which case all judges sit to hear the case en banc.
There are also several specialized courts in the federal judicial system. These include:
1c. United States Supreme Court
Overseeing all federal courts is the U.S. Supreme Court in Washington, DC. It consists of nine justices— the chief justice and eight associate justices.
The Supreme Court has selective control over most of its docket. By law, the cases it hears represent only a tiny fraction of the cases that are submitted. The Supreme Court has over 7,000 petitions (typically called petitions for a writ of certiorari) per year, not including thousands of petitions from prisoners; however, it hears arguments in only 100-150 cases.
The Supreme Court does not sit in panels. All the justices hear and consider each case together, unless a justice has a conflict of interest and must withdraw from hearing the case.
Source: This content has been adapted from Lumen Learning's "The Courts and the Legal Process" tutorial.