Question

What is combustion???

Answer 1

It is a chemical process in which a substance reacts with oxygen to give off heat. sometimes light is also given off during combustion, either as a flame(burning of wood) or as a glow(burning of magnesium ribbon)
[ If a glass is heated, combustion do not take place
I hope this was helpful :)

Answer 2

the rapid chemical combination of a substance with oxygen, evolving the production of heat and light.
********hope it helps*******