Nutritional Groups

Nutritional group organisms by their method of obtaining food energy.
Autotrophs produce their own food, and include organisms such as algae and most plants
Heterotrophs consume organic food found in their environments, and includes saprophytes (fungi), facultative parasites (Streptococcus pyogenes), most bacteria and most animals.
Hypotrophs are obligate parasites that require a host to grow. A good example of these is a virus.