Running rigging refers to the system of ropes, lines, and pulleys used on a sailing vessel to control the sails and masts. It allows sailors to adjust the position and tension of the sails, enabling the ship to harness wind power effectively. The running rigging includes various components such as halyards, which raise and lower sails, and sheets, which control the angle of the sails relative to the wind. Proper management of the running rigging is essential for optimal sailing performance and safety at sea.