The United States is a presidential system, in its early power structure, there is no element of political parties, only in the later political contest, political parties continue to play an increasingly important role in it. That is why the existing electoral system of the United States was birthed, which is unique to the United States. The referendum in US elections is called the popular vote, and each state has a different number of electoral votes depending on how many total Senate + House seats each state has in Congress.
In an election year, the general election is held in early November, when voters choose between several presidential candidates, and then each state counts the actual number of votes each candidate receives in that state, with more than half of the candidates receiving all of the state's electoral votes.
The final number of electoral votes is then obtained by adding up all the electoral votes received by the candidates in each state. Since there are 538 electoral votes in the nation*** (corresponding to 100 Senate seats + 435 House of Representatives seats + 3 seats in the District of Columbia), the presidential candidate who first receives 270 electoral votes will become the President-elect of the United States.
Expanded Information
Birth of the System
One of the points of contention at the Constitutional Convention of 1787 was how to elect a president. But there was no such thing as a "president," and the general term "executive" was used in the early Virginia and New Jersey proposals, as well as in later discussions and resolutions.
It was not until the final drafting of the Constitution by Morris that the title of President was adopted to designate the head of the new government. The method of electing the Executive was based on four main options at the Constitutional Convention: election by Congress, election by the governors of the states, direct election by the people of the nation, and election by the Electoral College.
Election by the governors of the states and direct election by the people met with more opposition at the outset, and the mode of election was then reduced to a choice between election by Congress and election by the Electoral College, of which the Congressional option prevailed at the outset.