The Founding Fathers established three branches of government to ensure that no one person or group of people could amass too much power. The three branches of the U.S. government are the executive branch, the legislative branch and the judicial branch. Each of the three branches is balanced by the powers of the other two coequal branches.
The executive branch is headed by the president, who serves as head of state and as the civilian commander in chief of the armed forces. The president is charged with implementing and enforcing the laws written by the U.S. Congress. Thus, he is responsible for appointing the heads of the various federal agencies. The vice president is also part of the executive branch and assumes the presidency if the president becomes incapacitated, dies or is removed from office.
The legislative branch writes the nation's laws. It is comprised of the House of Representatives and the Senate. The Constitution allots each state two senators; representatives are allotted to each state based on population. States with larger populations receive more representatives. Additionally, Washington D.C., Puerto Rico and four other U.S. territories have representatives, but they are not allowed to vote.
The judicial branch interprets the nation's laws. Federal judges are appointed by the president and approved by the Senate. The Supreme Court is the highest court in the land, and its decisions must be followed by all lower courts. Supreme Court justices are appointed for life by the president and approved by the Senate.