What is the difference between a primary and a caucus in the US presidential nomination?

While they are both means of selecting the democrat or republican nominations for the presidency they are very different process. Caucuses are a series of state-based meetings of party activists. They are found in only a few states that tend to be the smaller and less densely populated, such as North Dakota or Wyoming. Whereas a primary is an intra-party election to select a party’s nominee for the presidency an example of one would be New Hampshire. While different states have different rules in primaries as to who can vote (Some states only allow party members while others allow all voters to vote) they are often seen as more inclusive than caucuses. They also have different implications for the nomination process. Caucuses due to their smaller size and the fact that they cater towards party members which are heavily involved in the party, means that they attract a more ideological voter from each party, such as the conservative right in the republican party or the liberal left in the democratic. Whereas a primary which are an election rather than a meeting often give a more balanced indication of party politics. Size also matters in the nomination process, caucuses because they are held in smaller states typically nominate less delegates at a party’s convention than primaries which are held in larger states. As a result some presidential candidates may seek to concentrate more on primaries in larger states as opposed to the smaller caucuses in order to secure the nomination.