A primary election is an election in which voters in a jurisdiction select candidates for a subsequent election (nominating primary). In other words, primary elections are generally when each political party decides its nominee for the upcoming general election. Primaries are common in the United States, where they trace their origin to the progressive movement.
Elsewhere in the world, the nomination of candidates is usually the responsibility of political parties and does not make use of the public apparatus
for holding elections. The Primary Election in Iowa is a “Closed” primary, meaing a voter must affiliate formally with a political party in order to participate in that party's primary election. A primary election is held for the members of political parties to nominate candidates
for the general election.
The term “primary election” when it is used in the Code of Iowa, refers to the Primary Election held in June of even-numbered years. The primary election is held on the 1st Tuesday following the 1st Monday in June.