Structure of the Courts
District Courts

The United States district courts are the trial courts of the federal court system. Within limits set by Congress and the Constitution, the district courts have jurisdiction to hear nearly all categories of federal cases, including both civil and criminal matters. Every day hundreds of people across the nation are selected for jury duty and help decide some of these cases.
There are 94 federal judicial districts, including at least one district in each state, the District of Columbia and Puerto Rico. Three territories of the United States -- the Virgin Islands, Guam, and the Northern Mariana Islands -- have district courts that hear federal cases, including bankruptcy cases.
Appeals Court

An appellate court, commonly called an appeals court or court of appeals, is any court of law that is empowered to hear an appeal of a trial court or other lower tribunal. In most jurisdictions, the court system is divided into at least three levels: the trial court, which initially hears cases and reviews evidence and testimony to determine the facts of the case; at least one intermediate appellate court; and a supreme court (or court of last resort) which primarily reviews the decisions of the intermediate courts. A jurisdiction's supreme court is that jurisdiction's highest appellate court. Appellate courts nationwide can operate by varying rules.
Supreme Court
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The Supreme Court of the United States is the highest court in the United States. It has ultimate (but largely discretionary) appellate jurisdiction over all federal courts and over state court cases involving issues of federal law, and original jurisdiction over a small range of cases. The Court, which meets in the United States Supreme Court Building in Washington, D.C., consists of a chief justice and eight associate justices who are nominated by the President and confirmed by the United States Senate. Once appointed, justices have life tenure unless they resign, retire, or are removed after impeachment