The U.S. President's Office
"The President of the United States of America (POTUS) is the elected head of state and head of government of the United States. The president leads the executive branch of the federal government and is the commander-in-chief of the United States Armed Forces.
The President of the United States is considered one of the world's most powerful people, leading the world's only contemporary superpower. The role includes being the commander-in-chief of the world's most expensive military with the largest nuclear arsenal and leading the nation with the largest economy by real and nominal GDP. The office of the president holds significant hard and soft power both in the United States and abroad."
Accessed from https://en.wikipedia.org/wiki/President_of_the_United_States, August 23, 2016.
Article Two of the United States Constitution establishes the executive branch of the federal government, which carries out and enforces federal laws. It includes the President, the Vice President, the Cabinet, executive departments, independent agencies, and other boards, commissions, and committees.
Accessed from https://en.wikipedia.org/wiki/Article_Two_of_the_United_States_Constitution, September 13, 2016.