What makes steam-fired?

Answer 1

When water heats up to the point where it starts to boil, steam will descend from the water. So, water and high temperatures create steam. But, since other liquids also can create steam, I would say that if you boil a common liquid you will get steam.

Answer 2

This indicates the form of input energy and of the output energy.

The more proper phrase is coal (or wood or oil) fired and steam powered.

Such as steam engine, in which the wood is burnt in a furnace to heat water to steam, which is then used to drive some machinery.