This lecture examines white rot and brown rot fungi, two major groups of wood-decaying organisms that play essential roles in forest ecosystems. Students will learn how these fungi degrade wood, the differences in their enzymatic processes, and the characteristic patterns of decay they produce. The lecture also covers ecological significance, host range, and impacts on forestry and timber quality. Emphasis is placed on recognizing decay symptoms in the field and understanding the biology and life cycle of the fungi involved.