Heterotrophs, as opposed to autotrophs, refers to organisms that cannot synthesize organic matter by themselves, but must take exogenous organic matter as food and obtain energy by decomposing and oxidizing organic matter. That is to say, except for autotrophs, they are all heterotrophs.

Heterotrophs includes all animals, all fungi and non-chemoautotrophic bacteria.

It can also be roughly understood that all of them are heterotrophs except photoautotrophic bacteria, chemoautotrophic bacteria and plants.