Autotroph, Heterotroph and Mixotroph
The common part of the words “troph“ can be translated to sustenance, or more loosely translated to “get food from”. When combined with auto, as in autotroph, which means self, this can be read as “can make food for itself”
When combined with hetero, as in heterotroph, which means other or different, it means “needs to feed from someone or something else” When combined with mixo, as in mixotroph, which means a combination of, it is understood as an organism which can function both as autotroph or heterotroph, or some combination of the two.
Autotroph An organism that can create or absorb the energy it needs to stay alive from either sunlight (photoautotrophs) or chemicals (chemoautotroph or litoautotroph). Examples of photoautotrophs are most green plants, chemoautotrophs are often bacteria adapted to extreme locations.
Heterotroph Organisms that consume other organisms. It could be an animal consuming a plant or another animal.
Mixotroph An organism that relies on some mix of being heterotroph or autotroph. Common examples could be carnivorous plants, they rely on a mix of sunlight and ingested nutrients by consuming another organism, whether from the same trophic level or another.