Mushrooms, toadstools and moulds (such as Mucor) are multicellular fungi. Yeast is an example of a single-celled fungus.
Fungal cells have a cell wall made of chitin (remember that plant cell walls are made of cellulose).
Some fungi are pathogens, for example the fungal infection which causes athlete’s foot.
The hyphae contain many nuclei.
Fungi cannot carry out photosynthesis. Instead they use saprotrophic nutrition. They secrete enzymes onto their food so that digestion happens outside the fungal cells. They then absorb the digested organic products.