* it is the type of nutrition in which the organism cannot prepare food and depends on other organisms for it
* the form of this nutrition depends on type, method of obtaining, availability of food etc.
* **saprotrophic:** feed on dead and decaying matter (eg: fungi like bread mould, yeast, mushroom)
* **parasitic:** derive nutrition from *living* organisms by living on the body of the host (eg: fleas, lice, tapeworms)
* **holozoic:** ingest solid material which is digested and absorbed into their bodies (eg: humans, animals, insectivorous plants)