Fungi come in various forms including molds, mushrooms, and yeasts. They feed through absorption of nutrients from living or dead matter like plants, animals, or other fungi. Fungi live in damp environments and some are beneficial by aiding in processes like bread making, while others are harmful parasites that can cause diseases in plants and animals. Fungi are classified as unicellular yeasts, multicellular molds that can be parasites or break down organic matter, or multicellular mushrooms and toadstools that can be edible or poisonous.