The parts of a ship vary, depending on what kind of boat it is, but a few general parts are common to all types. Knowing the parts will increase your understanding when reading about boating related topics, and will also help you orient yourself when on board a ship. Many of the terms used are very old, as humans have been building, sailing, and talking about ocean going vessels for thousands of years.
The core of a ship is the structural keel, a heavily reinforced spine which runs along the bottom, in the middle. The keel supports the structure of the ship, and is the first part to be built, since it serves as a foundation. Some ships also have a hydrodynamic keel designed to increase their performance efficiency, which takes the form of a streamlined projection from the bottom of the boat to help it move quickly and smoothly through the water. The framework for the hull or shell, the body, is attached to the keel.
The hull is the most visible part of a ship, because it is the body of the watercraft. The hull makes the ship buoyant while providing shelter to those on board, and is divided by bulkheads and decks, depending on its size. Bulkheads are compartments which run across the ship from side to side, creating isolated areas, while decks are analogous to the floors of a house. A small boat may only have one primary deck, while larger ones may have over 10 decks, stacked from top to bottom.
The very bottom is known as the bilge, and the top is usually called the top deck. The top deck is broken up by the bridge, a covered room which serves as the command center. On larger ships, the top deck may have several levels, designed to isolate various parts. There may also be several deck areas topside, including the poop deck, the deck in the rear of the ship, and the afterdeck, located directly behind the bridge. The rig, including masts, rigging, and sails, rises up from the top deck.