A ship class is a group of ships of a similar design. This is distinct from a ship type, which might reflect a similarity of tonnage or intended use. For example, USS Carl Vinson is a nuclear aircraft carrier of the Nimitz class.
Two of the three Olympic-class ocean liners that were built; Olympic (left) and Titanic (March 1912)
Triple E class
A ship is a large vessel that travels the world's oceans and other navigable waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research and fishing. Ships are generally distinguished from boats, based on size, shape, load capacity and purpose. Ships have supported exploration, trade, warfare, migration, colonization, and science. Ship transport is responsible for the largest portion of world commerce.
Feeder ship Iris Bolten at Container Terminal Altenwerder, port of Hamburg, Germany
Fijian voyaging outrigger boat with a crab claw sail
One of the sailing vessels depicted in Borobudur temple, c. 8th century AD in Java, Indonesia
Egyptian sailing ship, c. 1422–1411 BC