What term describes a rapid chemical process that generates heat and usually light?

The term that describes a rapid chemical process that generates heat and usually light is combustion. Combustion refers to the chemical reaction between fuel and an oxidizing agent (usually oxygen) that produces heat and can produce light in the form of flames. This is the fundamental process that occurs during a fire.

While "fire" is often used in everyday language to describe the visible flames and heat produced during combustion, it is a broader term that encompasses the results of the combustion process rather than defining the chemical reaction itself. Combustion specifically highlights the rapidity and the generation of heat as well as light, which are key characteristics of chemical reactions involving burning materials. Understanding this distinction is important in the context of fire behavior and firefighting strategies.