Organic carbon, also known as carbonaceous material, refers to matter that contains carbon in its molecular structure. To describe this type of material in different contexts, various synonyms exist. For example, in soil science, organic matter refers to organic carbon-containing material decomposed or partially decomposed into humus. In the field of environmental science, biotic material or biogenic carbon is sometimes used to describe organic carbon in aquatic environments. In geology, black carbon, kerogen, or bitumen are synonyms for organic carbonaceous material, sometimes found in fossil fuels. These various synonyms for organic carbon help to clarify or emphasize particular aspects of this important component of the earth's biology and geology.