Fungi belong to a kingdom of organisms with almost 100,000 known species. In recent years, mycology has experienced great development: today we know that fungi are related to animals, not plants; that not all organisms called fungi are fungi; we can see the crucial role they play in the Earth's ecosystems, and we know, above all, that there is much left to learn. Through a general and updated review, this work deals with aspects related to them from the perspective of the diversity of life, both in the variety of their forms and in their relationships with plants and animals, including humans. The author's intention is to dismantle the stereotypical image that is generally held of fungi and to show why they will never cease to surprise us, because, as much fascination as they can generate in their detail, the astonishment they arouse in their diversity is even greater.