The president has power to sign or decline legislation, command armed forces, write opinions of his cabinet, adjourn congress, grant and reprieves and pardons, and receive ambassador.
Now both parts of our government are very important but many people say "the American president is the most powerful person in the world." Which is completely incorrect, congress has way more power than the president. For instance congress can declare war and the president only gets to command the military after the war is declared. Congress controls our money and you can’t have a nation without money.
But this may have been for a reason because if the president had too much power that could be bad. “Almost certainly, the founders intended Congress to have more important powers than the President and the Supreme Court. However, they placed many checks and balances on the legislature that have prevented absolute power in the hands of one branch” (UShistory.org) One person in control of the government leads to dictatorships. Which is not what our founding fathers worked so hard to