Live steam operation - garden railroading

A "live steam" engine is one which is actually driven by steam which has been produced by heating water until it
boils, just like the real full size steam locomotive.
This is quite different to an engine that has the outward appearance of a steam loco but has an electric motor driving the wheels.

Water is heated inside a sealed container (the boiler) until it boils and produces steam. It is kept boiling while ever steam is required.

In the larger scales and full size locomotives, coal or oil is the most common fuel used. In models, you have the choice of Butane gas, coal or spirit (meths or alcohol).

Large Scale engines are big enough to make live steam practical, however only a small percentage of hobbyists use live steam
Those that do are often nearly fanatic. To be bitten (or perhaps burned) by the live steam bug seems to be a terminal condition