What is a truffle? A plant? A mushroom?

The truffle is a fungus that grows underground and always lives in a symbiosis with certain trees, types of trees or shrubs.
A large number of bulbous mushrooms is referred to colloquially as truffles. At its deepest, it is the Tuber genus, which includes some of the most expensive and culinarily valuable mushrooms.
The marbled flesh inside the truffle is striking. The outer skin has bark-like protuberances whose shape, color and structure are important for truffle identification.
First and foremost you will recognize a rare, culinary high quality and expensive noble mushroom with a special smell and intense woody aroma.
The tubers vary in size, ranging from the size of a small nut to the size of a fist.