Organisms that survive and reproduce by inorganic nutrition are the corresponding words of organic nutritious organisms. Organisms that assimilate carbon by using energy obtained from chemical dark reactions such as respiration or photochemical reactions are called chemoautotrophs and photoautotrophs respectively. Representative examples of autotrophic microorganisms are red sulfur-free bacteria, red sulfur bacteria, green sulfur bacteria, nitrifying bacteria, sulfur bacteria, hydrogen bacteria, iron bacteria, carbon monoxide bacteria and so on.

Heterotrophs said that plants generally belong to autotrophs (except Nepenthes), and they can absorb inorganic substances from nature to synthesize organic substances, while heterotrophs can only maintain its life by absorbing organic substances, such as us.

Heterotrophs refers to those organisms that can only use the ready-made organic matter in the external environment as energy and carbon source, ingest these organic matters into the body, convert them into their own components, and store energy. Such as: fungi living in decay and parasitism, most kinds of bacteria.