How Do Iowa Caucuses Work?

As the nation begins to recover from football playoffs and college bowl games, political attention turns to Iowa, which shares Thursday evening fireworks with the Orange Bowl. How, exactly, do those caucuses work?

Presidential election primaries and caucuses are two different methods that political parties use to let party members (voters) select the presidential nominee. Only 13 states still use the caucus method for selecting convention delegates, and Iowa is the first.

Also, see Does Iowa Matter? and 2008 Election Central.