A ground fire can occur in any conditions and is where peat, coal, tree roots or other materials ignite and burn under the ground. Ground fires can burn through to the surface and become surface fires.
Surface fires are low to high intensity fires that burn on the surface of the ground. The tree canopy may be scorched but does not burn to the extent that it will carry a fire.
A crown fire occurs during fires of extreme intensity. A crown fire is when fire burns and spreads through the crown or canopy of trees. The influence of wind is greater in the tree canopy and where this canopy is interconnected or continuous, fires can spread incredibly quickly.