The executive branch negotiates treaties, and acts as head of state and commander in chief of the armed forces. This is the branch that the president is under. The executive branch also includes the vice president, and other important officials, such as the cabinet.
This branch has the power to make sure all laws are in check. The president (head of the branch) also has the power to veto laws, but the legislative branch can override the veto if they believe it should be a law.
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.
