A caucus is a meeting or grouping of supporters or members of a specific political party or movement. The exact definition of a caucus varies between different countries and political cultures. In the United States, caucuses are a method used by political parties to select candidates for an election. Here are some key differences between primaries and caucuses:

Primaries

• Primaries are run by state and local governments.
• Voting happens through secret ballot.
• Some states hold “closed” primaries in which only declared party members can participate.
• In an open primary, all voters can participate, regardless of their party affiliation or lack of affiliation.

Caucuses

• Caucuses are private meetings run by political parties.
• They are held at the county, district, or precinct level.
• Participants divide themselves into groups according to the candidate they support.
• At the end, the number of voters in each group determines how many delegates each candidate has won.

Historically, caucuses were the dominant method by which the major political parties determined their presidential nominees. Today, caucuses are less common than primary elections. However, political parties in some states, such as Iowa, still conduct caucuses as part of the presidential nominating process.