Inorganic substances can synthesize organic substances by themselves, which can be divided into light energy synthesis (various green plants or algae) and chemical energy synthesis (such as nitrifying bacteria and nitrosating bacteria).

What do you mean by strange creatures? (heterotrophic)?

Inorganic substances can't synthesize organic substances by themselves, but can only maintain metabolism by ingesting organic substances.

What is the fundamental difference between autotrophic ecosystem and heterotrophic ecosystem?

Can organisms in the system synthesize inorganic substances into organic substances by themselves?

What are there in heterotrophs?

Most microorganisms and most animals, etc.

What can heterotrophs be used as in the ecosystem?

Decomposer, consumer