How does a steamboat work?

Answer 1

It works with all those slave dudes rowing below deck innit.

Answer 2

Water is heated up by a boiler, until it produces steam, the steam then goes into a piston cylinder.
The steam pushes the pistoncylinder up to the top of its stroke. When the steam reaches the top a valve opens at the side of the cylinder and lets out the steam. Now there is place in the piston cylinder for new steam and the whole proces continous

something like that-_-