3 masted sailing ship

Tall ships.

More specifically, a Barque or Bark has three masts (possible more) fore and aft rigged mizzen mast.

Barquentine, three masts with all but the foremost fore and aft rigged.

A fully rigged ship, three or more masts, all of them square rigged

A Schooner, three or more masts with fore and aft rigged sails