Americans head to the polls on Tuesday in what has been described as its most divisive and heated race for the presidency.
As a Superpower, the US president will be at the forefront of forging international relations and be the commander-in-chief of the largest military in the world.
How the president is elected
This year's election will be conducted in a single round in all 50 states and the District of Columbia, a special federal district in Washington.
On the ballot form, voters will choose among the candidates for president and vice president. But, the tally of those votes will not determine the winner directly. Instead, it will determine the selection of a set of members of the electoral college, who pledge to support a given candidate.
Role of electoral college
The electoral college consists of 538 electors. A state has one elector for each of its members of the House of Representatives, and one for each of the state's two senators.
On December 19, electors will officially elect the president and vice president, in what is a mere formality.
A candidate needs to secure a majority of 270 electoral votes to become president. If no candidate receives the majority, the House of Representatives chooses the President and the Senate chooses the Vice President.
All states, except for Maine and Nebraska, use the winner-takes-all system. This means that the candidate who carries the majority of the popular vote wins the support of all the state's electors.
For instance, if Democratic candidate Hillary Clinton wins Florida, all of the state's 29 electoral votes go to her.
Maine and Nebraska use a proportional system in which two electors are chosen by popular state-wide vote and the popular vote in each congressional district determines the remainder.
Results can be expected as soon as polling stations close -- which is as early as 1800 ET and the last result expected around midnight in Alaska.
The president will be inaugurated on January 20, 2017.