I can understand non-US citizens "not getting" the government structure in the US. Some of us living with it don't get it. This overview should shed some light on the intent, organization, and checks and balances of the US Federal Government.

Intent

Oddly enough, the structure of the US Federal Government is intentionally convoluted and limiting. The creators of that structure (called the founding fathers) came from the perspective that a government with a concentration of power would limit individual rights and was thus inherently dangerous. They also represented many individual governments (colonies turned states) who agreed to come together for mutual defense and economic benefit, but who wanted to retain local governance for most issues. For these reasons, the federal government has only those powers specifically given to it by the founding fathers, with all other powers retained by the states. Hence we have a general tendency toward states rights and away from federal power.

Organization

With that background, here is a simplified overview of the Federal Government of The United States of America. There are three branches of government:

1. The Legislative Branch creates laws. It is comprised of two bodies (Senate and House of Representatives) that together are referred to as Congress. Both must agree before a law becomes effective.

The House of Representatives is proportional to population, with each state getting at least one representative that we call Congressmen or Congresswomen. They have two year terms and the whole lot of them are up for election at the same time every two years, so they really are always running for office and try to be very responsive to the will of the people. When I was an intern in a Congressman's office in Washington DC, I found the congressmen were ALL sensitive to any request from someone in their district.

In the Senate, each state gets two Senators regardless of population. Senators have six-year terms, so about 1/3 of them are up for election every two years when the entire House is up. Senators tend to think in broader terms and be less responsive to requests from constituents. We (the founding fathers) don't trust the Senate to manage our purse, so legislation that has to do with budgets and taxes (anything to raise or spend money) has to be introduced in the House. The Senate can't initiate those, they can only respond to ones passed by the House. There is another lesson on how a bill becomes a law, but not today.

2. The Executive Branch is responsible to carry out the laws and see that they are enforced. This is headed by the President and Vice President and all the federal government agencies including the FBI, . We also make the President the Commander in Chief of the armed forces because we want a civilian in charge of the military.

The President and VP are elected in a convoluted manner. As much as we talk about encouraging the spreading of democracy, we do NOT live in a democracy in the strictest definition. There are very few things that citizens directly vote on. We don't even directly vote for President. Our presidential election is done through an electoral college with each state getting the number of Senators and Representatives they have as their block of votes in the electoral college. The ballot may list the candidates, but we are voting for electors who are "committed" to voting for those candidates ON THE FIRST BALLOT of the electoral college. If one gets a majority, then they are done with that office and move on to VP, but if one doesn't get a majority of the electoral college on the first ballot, they vote again and can change who they vote for!

(By the way, our Vice President serves as President of the Senate, and gets to cast a vote only in case of a tie.)

3. Then we have the Judicial branch, which is intentionally the weakest branch of government. The federal courts are expected to hear cases concerning federal laws. The appeal process within the federal courts eventually leads to the Supreme Court which has the ability to overturn laws passed by Congress.

Checks and Balances

Federal Judges are appointed by the President, but only with the "advice and consent" of the Senate. The President can veto legislation of Congress, but Congress can override a veto with a super-majority. Only Congress can declare war, but Congress cannot manage military operations. It is all about checks and balances to keep there from being too much power in too few hands.