How does a steam engine do work?

(a) Steam turns a turbine.

(b) Steam enters a cylinder and pushes a piston.

(c) Steam expands and spins an axle.

(d) Steam causes wheels to turn.

As water is heated up, it turns to steam

steam expands and enters a cylinder

a piston is pushed by the expanding steam in the cylinder

this action is the steam doing work on the piston

the motion of the piston is translated into a rotation motion, which can then be used to drive stuff