Fungi are eukaryotic, heterotrophic, i.e. they do not make their own food. They may be saprophytic or parasitic.
Usefulness of fungi:
Fungi are commonly used to make food and drink. Fungi add taste, flavors, fluffiness, to the food items.
Mushrooms are the largest fungi. These are edible fungi and rich in proteins and vitamin B.
In cheese processing industries, several species of Penicillium and Aspergillus give different flavors to the cheese, for example, flavors of Roquefort cheese is imparted by Penicillium roquefortii.
Yeast is used in bakeries to prepare bread dough.
In beverage industries, yeast is widely used to prepare alcoholic and non-alcoholic drinks. Yeast is a unicellular, eukaryotic fungi.
The yeast Saccharomyces cerevisiae, is also known as brewer's yeast. Malted cereals and fruit juices are fermented to manufacture alcoholic beverages such as wine, beer, rum, etc. in beverage industries.