Fungi are generally multicellular eukaryotic organisms that cannot make their food.
It is different from plants, bacteria, and some protists because it contains chitin in its cell walls, while plant cell walls contain cellulose.
Mushrooms:
A mushroom is the fleshy, spore-bearing fruiting body of a fungus. It grows above ground, on soil, or on any source of food.
It is considered a fungus because it contains no chlorophyll and is a saprophyte (any fungus, plant, or microorganism which lives on the dead and decaying matter).