Decomposer

Decomposers are organisms that break down dead organisms and release the nutrients from the dead matter into the environment around them. Decomposition relies on chemical processes similar to digestion in animals; in fact, many sources use the words digestion and decomposition interchangeably. In both processes, complex molecules are chemically broken down by enzymes into simpler, smaller ones. The term "digestion," however, is commonly used to refer to food breakdown that occurs within animal bodies, and results in the absorption of nutrients from the gut into the animal's bloodstream. This is contrasted with external digestion, meaning that, rather than swallowing food and then digesting it using enzymes located within a GI tract, an organism instead releases enzymes directly onto the food source, which is what decomposers do as compared to animals. After allowing the enzymes time to digest the material, the decomposer then absorbs the nutrients from the environment into its cells. Decomposition is often erroneously conflated with this process of external digestion, probably because of the strong association between fungi, which are external digesters, and decomposition.