Fungi are mostly made of many cells. Fungi made of single cells are called yeasts. They are also part of a group of living things called 'Eukaryotes', just like animals and plants. We're closer to mushrooms and yeasts than you think!
Lots of people, when they see fungi, think of mushrooms, however there are lots of different types of fungi, not just mushrooms and toadstools.
Fungi are very important because they break down waste. The leaves on the bottom of a forest would get higher and higher if fungi were not there to eat it.
Fungi are also important producers of food for humans. Also, yeasts are used to make wine, beer, and bread. Some fungi are bad for our food, however, such as mould.