What is the difference between presidential primaries and caucuses?
A primary is an election that happens to take place before the main election. It is run with secret ballots and strict rules under state law. Voters may or may not be limited in the what they may vote for – some states restrict voters to candidates from their declared party, others do not. A caucus is a bunch of people of a political party who show up at a party meeting and decide, by whatever system they want to use, who their choice is.