The Internet is a wonderful resource for information. If you can’t find an answer in your text book, you can try using Google to search for it.
Anyway, fungi are microorganisms that belong to Kingdom Fungi which is separate from plants, animals and bacteria. They are found almost everywhere, especially in environments such as soil. They include filamentous ones such as moulds (the fuzzy stuff that grows on spoilt bread) and single cell ones such as yeast (used to make bread and beer). Mushrooms are also a common type of fungi.