What is combustible, flame and fuel.​

Fuel is a fuel component that undergoes oxidation during combustion in the chamber of an air-jet engine or a liquid rocket engine.

Flame is a phenomenon caused by the glow of an incandescent gaseous medium, in some cases containing plasma and/or dispersed solids, in which physical and chemical transformations of reagents occur, leading to glow, heat release and self-heating. The gaseous medium of the flame contains charged particles (ions, radicals), which causes the presence of electrical conductivity of the flame and its interaction with electromagnetic fields.

Fuel in the broad sense of the word is a substance that can release energy during certain processes, which can be used for technical purposes