Most plants are autotrophs because they make their own food. Some plant species are parasitic, meaning they get their nutrients from other sources. Parasitic plants are heterotrophic.
Any plant with green leaves is classified as an autotroph. The definition covers trees, mosses and flowering plants, to name a few. Most plants use photosynthesis to produce food in the form of sugar.
Plants are not the only organisms classified as autotrophs, although they are one of the most well-known examples. Phytoplankton, algae and some types of bacteria are also able to make their own food. Some of these organisms use chemosynthesis instead of photosynthesis.
Chemosynthesis uses the energy generated by chemical reactions to produce food. Some of the bacteria that live in the ocean use hydrogen sulfide to power chemosynthesis.
Parasitic plants are unable to make their own food. These plants feed off the roots or stems of their hosts.