Answer:
The power of the Executive Branch is vested in the President of the United States, who also acts as head of state and Commander-in-Chief of the armed forces. The President is responsible for implementing and enforcing the laws written by Congress and, to that end, appoints the heads of the federal agencies, including the Cabinet. The Vice President is also part of the Executive Branch, ready to assume the Presidency should the need arise.
The Cabinet and independent federal agencies are responsible for the day-to-day enforcement and administration of federal laws. These departments and agencies have missions and responsibilities as widely divergent as those of the Department of Defense and the Environmental Protection Agency, the Social Security Administration and the Securities and Exchange Commission.
Including members of the armed forces, the Executive Branch employs more than 4 million Americans.
The President
The President is both the head of state and head of government of the United States of America, and Commander-in-Chief of the armed forces.
Under Article II of the Constitution, the President is responsible for the execution and enforcement of the laws created by Congress. Fifteen executive departments — each led by an appointed member of the President’s Cabinet — carry out the day-to-day administration of the federal government. They are joined in this by other executive agencies such as the CIA and Environmental Protection Agency, the heads of which are not part of the Cabinet, but who are under the full authority of the President. The President also appoints the heads of more than 50 independent federal commissions, such as the Federal Reserve Board or the Securities and Exchange Commission, as well as federal judges, ambassadors, and other federal offices. The Executive Office of the President (EOP) consists of the immediate staff to the President, along with entities such as the Office of Management and Budget and the Office of the United States Trade Representative.
The President has the power either to sign legislation into law or to veto bills enacted by Congress, although Congress may override a veto with a two-thirds vote of both houses. The Executive Branch conducts diplomacy with other nations, and the President has the power to negotiate and sign treaties, which also must be ratified by two-thirds of the Senate. The President can issue executive orders, which direct executive officers or clarify and further existing laws. The President also has unlimited power to extend pardons and clemencies for federal crimes, except in cases of impeachment.
With these powers come several responsibilities, among them a constitutional requirement to “from time to time give to the Congress Information of the State of the Union, and recommend to their Consideration such Measures as he shall judge necessary and expedient.” Although the President may fulfill this requirement in any way he or she chooses, Presidents have traditionally given a State of the Union address to a joint session of Congress each January (except in inaugural years) outlining their agenda for the coming year.
The Vice President
The primary responsibility of the Vice President of the United States is to be ready at a moment’s notice to assume the Presidency if the President is unable to perform his duties. This can be because of the President’s death, resignation, or temporary incapacitation, or if the Vice President and a majority of the Cabinet judge that the President is no longer able to discharge the duties of the presidency.
https://www.whitehouse.gov/about-the-white-house/the-executive-branch/