Types of ships:

Ships are difficult to classify, mainly because there are so many criteria to base classification on. One classification is based on propulsion; with ships categorised as either a sailing ship or a motorship. Sailing ships are ships which are propelled solely by means of sails. Motorships are ships which are propelled by mechanical means to propel itself. Motorships include ships that propel itself through the use of both sail and mechanical means.
Other classification systems exist that use criteria such as:
• The number of hulls, giving categories like monohull, catamaran, trimaran.
• The shape and size, giving categories like dinghy, keelboat, and icebreaker.
• The building materials used, giving steel, aluminum, wood, fiberglass, and plastic.
• The type of propulsion system used, giving human-propelled, mechanical, and sails.
• The epoch in which the vessel was used, triremes of Ancient Greece, man' o' wars, eighteenth century.
• The geographic origin of the vessel, many vessels are associated with a particular region, such as the pinnace of Northern Europe, the gondolas of Venice, and the junks of China.
• The manufacturer, series, or class.
Another way to categorize ships and boats is based on their use, as described by Paulet and Presles.[28] This system includes military ships, commercial vessels, fishing boats, pleasure craft and competitive boats. In this section, ships are classified using the first four of those categories, and adding a section for lake and river boats, and one for vessels which fall outside these categories.