Here's a breakdown:

Multicellular Fungi:

* Mushrooms, toadstools, and bracket fungi: These are the most recognizable forms of fungi and consist of a network of thread-like hyphae that intertwine to form a complex structure.

* Molds: These are multicellular fungi that grow as fuzzy colonies on surfaces, also composed of hyphae.

* Truffles: These are underground fungi that form a fleshy, fruiting body, and are also multicellular.

Unicellular Fungi:

* Yeasts: These are single-celled fungi that reproduce by budding. They are responsible for fermentation in bread, beer, and wine.

* Some molds: While most molds are multicellular, some species can exist as single-celled organisms during certain stages of their life cycle.

Important to note:

* Many fungi have life cycles that include both multicellular and unicellular stages. For example, some yeasts can form hyphae under certain conditions.

* The distinction between multicellular and unicellular fungi is not always clear-cut, and there are some species that defy easy categorization.

So, the answer to your question is that fungi can exist in both forms, depending on the species and its life cycle stage.