The United States holds elections every two years. Once every four years there is a presidential election as well as congressional elections. The Legislature consists of two chambers - the House of Representatives and the Senate.
Senators are the more senior and tend to be less partisan.
For legislation to be passed it has to be approved by both chambers of Congress and then agreed to by the president. The Judiciary is made up by three levels of courts. The famous Supreme Court has nine judges which decide constitutional issues. It has 435 members representing districts across the United States. The upper house of Congress, the Senate, has 100 members.