Plants are classified by organisms that are autotrophs, or make their own food. They take the suns energy into chloroplast and turn it into nutrients it can use. a bi product of this is oxygen that animals need to live.
Animals are organisms that are heterotrophs, or cannot make their own food. They breathe in oxygen made by plants and make carbon dioxide that the plants need to survive.
Protists are mostly single celled organisms. They are all microscopic. the difference between them and bacteria are their chemical makeup; protists are more complex cells. some protists make their own food, but some take nutrients in by eating animals.
Fungi are mostly multicellular organisms with many complex cells. they cannot make their own food, they obtain it from decaying plants around them.
Eubacteria are complex single celled organisms. These bacteria are the most known, and most bacteria fall into this category. They cannot make their own food, they get it from the area around them. Eubacteria and archaebacteria have different chemical makeups.
Archaebacteria are mostly single celled organisms. They cannot make their own food, but obtain it from the environment around them. They can survive in very harsh environments.