What is heat of combustion

Heat of combustion is the heat which is generated when we burn the things. And so on when we cook with a gas stove.
It's the heat which you often see in your life.
Oxygen is usually concerned with action of combustion. Oxygen has assistant inflammability which help the things burn. If oxygen is a lot, the things burn too much. If oxygen is little, the things hardly burn. So oxygen concentration on the earth is the best.