Primary election period
Presidential candidates are selected in primary elections or caucuses. In a caucus the candidates are chosen by party activists – first on a county and then on a state level. Primary elections are on a state level and people cast their ballots for the candidate they prefer or for a delegate who will support a certain candidate at the party's convention. There are ‘closed primaries’ where only registered members of the party are allowed vote and ‘open primaries’ where voters can also cast their ballots in another party’s primary. Which procedure is followed, depends on the laws of each particular state.
At the Democratic / Republican National Convention, the parties nominate and confirm a candidate for president and vice president. The national convention officially ends the primary election period and starts the general election period.
General election period
During the general election period, there is a lot of advertising, campaigning and debating going on by which the candidates try to win votes.
The funny thing is that there is hardly any advertising to be seen in states where one candidate is already sure to win. The campaigns concentrate on so called swing states – states where people do not usually have a strong party affiliation.