What is an autotroph?

An Autotroph is an organism that only needs one simple compound in order to grow.

An autotroph is an organism capable of making organic food molecules from inorganic sources via photosynthesis (involving light energy) or chemosynthesis (involving chemical energy).

Autotrophs are the producers in a food chain, such as plants on land or algae in water.

The term itself means self-feeder.