The carrack was a large trading and fighting vessel of the Mediterranean from the 14th to the 17th centuries. It started as a two-master with one largesquare-rigged sail on each, but by the early 16th century topsails were being used and by the end of that century four masts were common. Its hull was carvel-built but it was larger than the caravel. It was the ship of choice for the Portuguese transportation of troops and supplies to Brazil and India during the 16th century.
In about 1450 a Portuguese ship-builder wrote that he considered there was very little difference between the nave, the nao the carrack and the German hulk. It is likely that it is the origin of all the three-masted sailing ships that would dominate trade and war until the advent of steam-power.
- Square-rigged refers to the set of the sails on what most people would consider the classic large sailing ship – the galleon or the clipper for example, or any large warship of the age of sail. The sails are set across the bow to stern line of the vessel and are four-sided and attached to yards that can be angled according wind direction. (Very few vessels in the last 500 years have been purely square-rigged – almost every ship has had triangular staysails set between the masts or from the foremast to the bow and most have a gaff-sail on its stern-most mast – usually called a “spanker” – whether or not there is square rigging on that mast.)
Reference: "The Oxford Companion to Ships and the Sea."