A1.2.4.1 Combustion
Combustion is commonly known as burning. It is the burning of a fuel and oxidant to produce heat. The fuel can be gaseous, solid or liquid.
There are more end products of combustion than just heat. A combustion process may also result in light and pollutants.
An animated diagram of the carbon cycle is available here:
http://www.forestry.gov.uk/forestry/infd-7m8fe2