The executive branch consists of the president, vice president, and 15 cabinet-level departments such as State, Defense, Interior, Transportation, and Education. The primary power of the executive branch rests with the president, who chooses his vice president, and the members of his cabinet who head their respective departments. A crucial function of the executive branch is to ensure that laws are implemented and enforced to facilitate the federal government's day-to-day responsibilities such as collecting taxes, safeguarding the homeland, and representing U.S. political and economic interests around the world. The legislative branch is made up of the Senate and the House of Representatives, collectively known as Congress. There are 100 senators; each state has two. Each state has a different number of representatives, the number of which is determined by the state's population. Currently the members are 435