The functions of the three branches of the U.S. government are as follows: the legislative branch makes and enacts laws, the executive branch carries out laws, and the judicial branch evaluates and interprets laws. Combined, the three branches of government provide a system of checks and balances.
The legislative branch is made up of the House of Representatives and the U.S. Senate. The House of Representatives is composed of 435 members apportioned among the 50 states, the District of Columbia, and U.S. territories in proportion to population. The Senate is composed of 100 members, with two senators per state. The legislative branch is responsible for introducing and enacting legislation, confirming or rejecting appointments by the president, and declaring war.
The executive branch consists of the president, vice president, Cabinet and executive departments. Certain agencies, commissions and committees are also part of this branch. Foremost among the many duties of the president is to lead the federal government and faithfully execute the laws of the United States. The vice president, Cabinet and other agencies serve in more supporting and advisory roles. While the vice president is elected along with the president, Cabinet members are generally nominated by the president and must be confirmed by the Senate.
The judicial branch is composed of the Supreme Court and federal courts. Their specific role is to interpret laws, apply the law as necessary, and rule on the constitutionality of laws. The president nominates Supreme justices, and they must be confirmed by the Senate.