The proper definition of fungi is a kingdom of substances made of different organisms such as algae, and mushrooms.
Fungi are usually referred to as plants, but they are not. Fungi differ from plants because they do not photosynthesize, meaning they cannot produce their own food. Fungi feed on trees, and dead matter such as dead plants and animals.
There are two different types of fungi, saprophytes and parasites. Saprophytes are the fungi that feed on dead matter. Parasites have symbiotic relationships. Symbiosis is a relationship in which one organism is on, near, or even inside another organism. There are three types of symbiosis. One is commensalism, in which one organism benefits from the relationship and the other is unaffected. The next type is mutualism. This is when both organisms benefit from the relationship. The last is parasitism. This when one organism benefits from the relationship (the parasite) and the other is hurt by the relationship (the host).
The next fungi is mushroom. They have gills, a cap, a stalk, and an annulus. The annulus is a small ring that wraps around the stalk. For a mushroom to live, it must have warm temperature, food, oxygen, and moisture (water H2O). A mushroom grows from a single spore; it grows in the ground after being released from the gills of another mushroom which becomes hyphae and then grows into a single mushroom. 3/4 of the spores do not survive, but there are so many of them some get to grow into brand new baby mushrooms. Since a mushroom is fungi, its food source is dead matter. Mushrooms spread by eating up all the food they have and need to go off in search of more.
Mold is another type of fungi. There are many different types of mold also. There is yeast mold and penicillin mold.
Yeast mold is used for making bread, beer, and wine. Yeast mold, since it is in the fungi kingdom likes temperatures that are not too hot, not too cold; yeast likes warm temperatures, and it likes moist places (H20). And of course, it needs food. Yeast cells reproduce by budding, which is where the yeast multiply into two and then one releases itself from the other. That is how yeast cells reproduce.