Answer:
When fuels burn in combustion reactions, they release useful thermal energy (heat). Combustion reactions are used to heat our homes, power most cars, and to generate a lot of our electricity.
Energy production from the reaction is what drives life and human greed. We stay alive by eating carbon-rich compounds, which are then burned in a spectacularly controlled and efficient manner to provide us with energy. It is the all-important energy term in the combustion equation that has made life on Earth possible