Breakdown of the detritus by detritivores is an initial step, then degradation of the detritus into simple inorganic substances, by bacterial and fungal enzymes is another step of decomposition which are respectively called as

Detritivores (e.g., earthworms) break down detritus into smaller particles. This process is called fragmentation.

Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is called catabolism.