What are the jobs of the Executive Branch of the United States?

The executive branch is responsible for enforcing the laws of Congress.  The President of the United States is the head of the executive branch and chooses the heads of all of the executive departments.  When Congress passes a law, the President supervises fifteen executive departments that can enforce that law. Examples of executive departments are the Department of State, Department of Defense, Department of Commerce, and Department of Education.  Depending on the type of law that is passed, one of those departments will execute or enforce the law.  Within the larger departments are hundreds of smaller agencies like the Federal Bureau of Investigation and the Securities and Exchange Commission.  All of these agencies have been created to enforce federal laws.  

The Constitution of the United States also states that the President is commander-in-chief of the armed forces.  Because of this, the Executive Branch is responsible for the organization of the branches of the military.  The president, as head of the Executive Branch, also has limited legislative power in that he/she can veto laws or establish Executive Orders.