Eli5: If fire is not plasma, what is it?

Question

Just read somewhere that fire is unique to earth, I don’t understand

In: Chemistry

Answer 1

Fire is not realy unique to earth, but it requires oxygen(O2) something that does not naturaly occure on other planets, because its produced by plants here on earth.

And fire can contain or produce plasma, but the light itself is not only plasma its just hot gas thats hot enough to glow.