For water propulsion, the most common types are underwater propeller, water jet[?], and for nuclear submarines[?], magneto-hydrodynamic. Sails are also common, and historically represented the most significant form of early propulsion for large watercraft. Oars were probably the earliest form of water propulsion.
For air propulsion, the most common types are propeller, turboprop, turbojet, ramjet, scramjet, and rocket propulsion.
For ground propulsion, virtually all of the above have been used at one time or another. Most ground vehicles use wheels of one sort or another, but the power plant used to drive them can vary widely. In modern times, most vehicles use some form of internal-combustion engine, with electric motors supplementing them. Historically, vehicles were drawn by animals.
For these and other types of transportation, see transport.
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