A boat is a watercraft or vessel, usually smaller than most ships. Some boats are commonly carried by a ship or on land using trailers - indeed, one of the definitions of a boat is a watercraft that can be carried by a ship.
See also: Glossary of nautical terms and Naval architecture
Ancient boat in an Egyptian tomb painting from about 1450 BCE
The roughly horizontal, but cambered structures spanning the hull of the boat are referred to as the "deck". In a ship there are often several, but a boat is unlikely to have more than one. The similar but usually lighter structure which spans a raised cabin is a coarch-roof. The "floor" of a cabin is properly known as the sole but is more likely to be called the floor. (A floor is properly, a structural member which ties a frame to the keelson and keel.) The underside of a deck is the deck head. The vertical surfaces dividing the internal space are "bulkheads". Some are important parts of the vessel's structure. The front of a boat is called the bow or prow. The rear of the boat is called the stern. The right side is starboard and the left side is port. Many boats these days have a section called the gralper. This section is designed to reduce water flow to the non-aerodynamic parts of the boat.