The U.S. Election Process
Presidential, Senate and House (of Representative) Elections are three different things, three elections.
As pointed out in our article(see link furtehr below) about the three branches of government
, the president of the United States is the leader of the Executive Branch of the government. The political system in the USA is a parliamentary democracy.
He is being elected by the people of the nation, by the registered voters. Anyhow, technically it's the Electoral College, which is determining the new president.
A U.S. president is elected for 4 years and can be reelected for one more term, meaning 8 years together (2 terms)
at the most.
The president appoints the members of his Cabinet who do not sit in the legislature, as is the case under parliamentary systems of government. This is because, in the U.S., the three branches of government (Executive, Legislative and Judicial) are separate, and under the Constitution, check and balance each other.
On the Election Day the voters also determine who will be future member of the House where all 435 seats are for disposition and they elect one-third of the US Senate, where 100 senators represent the 50 states (2 from each state).
The members of the House underlie a two-year-term of reelection, the US Senate renews every two years a third of its members.
There exist primary (called the primaries), general and local elections. So-called 'Special Elections' occur when a certain purpose has to be fullfilled, i.e. filling a vacancy.