The term JIB, BOOM OR GAFF refers to three different types of spars used in sailing. A jib is a triangular sail that is set at the front of the boat and is used to control the direction of the boat. A boom is a long pole that is attached to the mast and is used to control the angle of the sail. Finally, a gaff is a four-sided SPAR that is attached to the mast and is used to support the upper edge of the sail. All three of these spars are essential components of a sailing vessel and are used to control the direction and speed of the boat.