Fire is not a physical thing in the traditional sense. It is a chemical reaction known as combustion. When a material combines with oxygen, it undergoes a chemical change that releases energy in the form of heat and light. This process is what we perceive as fire.
Fire consists of several components: heat, fuel, and oxygen. These elements must be present for fire to occur. The heat provides the energy needed to start the reaction, the fuel is the material that burns, and oxygen supports the combustion process.
While fire is not a physical object, it does have physical properties. It emits light and heat, which are forms of energy. The flames you see are the visible part of the fire, consisting of hot gases and plasma. These gases are the result of the combustion process and can vary in color depending on the materials being burned.
In summary, fire is a chemical reaction rather than a physical object. It is a process that transforms materials into different substances while releasing energy in the form of heat and light.