Courts of Appeals
The 13 U.S. Courts of Appeals sit between the Supreme Court and the U.S. District Courts. Each of the 12 regional circuits has a Court of Appeals. The 13th Appeals court is the Federal Circuit that hears appeals to patent cases and other specialized cases. The map above shows the 11 numbered circuits, as well as the D.C. Circuit and the Federal Circuit (both located in Washington D.C.).
Each appellate court hears challenges to cases adjudicated in district courts within its circuit. There is no jury in an Appeals Court. Instead three judges review the decisions of the district courts and determine whether the trial was held fairly and the law applied properly.
U.S. District Courts
U.S. District Courts are the first level of the federal governments trial courts. They are also called circuit courts. There are 94 District Courts organized into twelve regional circuits and one federal circuit. There is at least one district court in every state, along with one in the District of Columbia and one each in the territories of Guam, the Northern Mariana Islands, Puerto Rico, and the U.S. Virgin Islands