Sail types refer to the various designs and shapes of sails used on boats and ships to harness wind power for propulsion. Common types include mainsails, jibs, and spinnakers. Each sail type serves a specific purpose, such as providing stability, speed, or maneuverability, depending on the sailing conditions and the vessel's design. Sails can also be categorized by their rigging configurations, such as sloop, ketch, and catamaran. These configurations determine how sails are set and adjusted, affecting the boat's performance. Understanding different sail types helps sailors optimize their vessels for various wind conditions and sailing styles.