Stage 1 ? Primaries and caucuses
US presidential elections always take place on the first Tuesday after the first Monday in November. The ball is set into motion in January of that year when the first step in choosing parties? candidates takes place, i.e. a primary.

A primary is a state-level election in which voters choose a candidate affiliated with a political party to run against a candidate who is affiliated with another political party in a later, general election.

While in other countries the party will choose a candidate, in America the choice rests with voters. A primary may be either open ? allowing any registered voter in a state to vote for a candidate to represent a political party, or closed ? allowing only registered voters who belong to a particular political party to vote for a candidate from that party.

Some states, however, prefer the caucus system to select its delegates. A caucus is an informal meeting with candidates and potential voters in which participants discuss their preference for a certain candidate, and delegates, pledged to a particular candidate, are selected to go to party conventions. Iowa is one of 15 US states that choose its delegates this way.

In the case of primaries, the final selection is made at the party?s national convention by delegates. Candidates need a majority of delegates at the convention to win.

Stage 2 ? Conventions
After a few months of primaries and caucuses throughout the country, it is time for national party conventions, traditionally held in the summer preceding the election.

During this time the major states will, with great fanfare, nominate their candidates for president and vice president. Third parties and independent candidates follow different procedures according to the individual State laws.

The names of the duly nominated candidates are then officially submitted to each state's chief election official so that they might appear on the general election ballot.

Stage 3 ? Campaigning
The third stage of the elections is dedicated to campaigning as things heat up with huge publicity campaigns, countrywide televised debates, and the race to secure ?swing states? ? states seen as winnable by either the Republicans or Democrats.

The battle for swing states, or battleground states, as they are also known, usually becomes the primary focus of the last few weeks of campaigning as candidates aim to secure the votes of the electoral college, which is the group of people who directly elect the president and vice president.

This stage of the campaign is usually shorter than the first stage, which involved the primaries. Policies are also refined during this stage as candidates aim attract the supporters of those who have been eliminated.

Stage 4 ? Voting and electoral colleges
Presidential candidates have to wrap up their campaigns eventually as voting day draws closer. After votes have been cast on voting day, counting begins, and a preliminary result is usually known within 12 hours after the polls have closed.

Next its to the electoral college ? a system in which each state is represented by a number of individuals proportionate to its seats in Congress, that is, two Senators and a number of Representatives based on the state's population.

According to the BBC Online, the number of electoral college members varies in each state; and the number of members reflects the state's representation in Congress. Whoever wins the most votes in a state wins all of that state's electoral college members.

Once a candidate gets a majority of members from across the states, the election is over in the public's mind, according to the BBC Online. But in fact the electoral college members do formally meet and vote for the president. College members are not legally bound to vote for the winning candidate or according to their party allegiance, but instances when they have not are rare, says the BBC Online, adding that votes are formally counted in front of Congress the following January.

It was through garnering a majority vote in the electoral college four years that George W. Bush won the presidential race in 2000.