Off topic: power plant terminology

Hello guys, I need a small help about English engineer's terminology used in power plants. I thought that term "Thermal power plant" means that fuel (coal) is burned to produce steam that will rotate turbine and so on. Now on one place I found term "Combustion plant" and in that article there are following terms:
Thermal plant, Combustion plant and Hydroelectric plant.
I know what is Hydroelectric plant (water rotates turbine) but what is the difference between Combustion and Thermal plant. Maybe Combustion plant use different kind of fuel (for example natural gas or oil, but I'm not sure about this. Can Combustion plant use coal and when term Combustion is used comparing with term Thermal?
I hope you'll help me.
I ask this question because in my dictionary terms "combustion" and "burn" have sam meaning...

Combustion would be natural gas,diesel,gasoline.Thermal has a broad spectrum going from waste heat recovery to coal fired, upto nuclear power. Anytime you are using a heated medium to produce the steam for the turbines it is themal.

Gas turbines & Heat Recovery Steam Generators

Thermo power plant is a term used to refer to the conventional power plants build in the 50’s, 60’s and 70’s and 80’s which were mostly fossil fuel (i.e. fuel oil, coal, etc.) and nuclear.



Nowadays is gaining more popularity the construction of HRSG and combined cycle power plants. Both design use primarily gas turbines … may be they are using the term “combustion” to refer to this type of power plants.



Regards,

Thermal power plant can also be geothermal [like the few in Iceland that recently got covered in lava] and solar thermal [where the solar energy is focused to heat a chamber of something to drive generators]