A two-masted sailing vessel is commonly known as a ketch or a brig. The term was also used as shorthand for brigantine in the 1700s, but the ships eventually had different specifications that led to the specific use of the word "brig." Other names also include yawl and schooner.
Brigs were two-masted ships with square sails on both masts, developed as a variant of brigantines. They had fore-and-aft boom-sails on the rear mast. These types of ships belong to a larger category of sea vessels called "tall ships".
Brigs were commonly used as warships, and were favored by pirates due to their maneuverability and fast speed. They were capable of carrying 10 to 18 guns, and were used in many naval battles, such as the Battle of Lake Erie between the British and America.