1. Carbon Dioxide (CO2): This is a major greenhouse gas, produced when carbon-containing fuels like wood, oil, or natural gas are burned.

2. Water Vapor (H2O): Water is formed when hydrogen in the fuel combines with oxygen from the air during combustion.

3. Ash: This is a solid residue left behind after combustion, containing the non-combustible parts of the fuel and any impurities. The composition of ash varies depending on the fuel.

Important Note: Depending on the type of combustion and the fuel used, other byproducts can be released, including:

* Carbon Monoxide (CO): A highly poisonous gas.

* Nitrogen Oxides (NOx): Contribute to smog and acid rain.

* Particulate Matter (PM): Tiny particles that can cause respiratory problems.

* Sulfur Dioxide (SO2): Contributes to acid rain.