Mushrooms Are Actually The Fruit Of Fungi
The mushrooms we eat are just the temporary fruits of a vast, hidden organism. Most of the living fungus actually exists as an invisible underground network, meaning we are harvesting only the reproductive parts.
Think of the mushroom as an apple growing on a tree; the main body of the organism remains safely tucked away in the soil or wood. This underground web, known as mycelium, can stretch for miles and live for decades. Because mushrooms are merely the fruiting bodies, picking them does not kill the main organism. It is a fascinating way for nature to spread spores while the true heart of the fungus keeps growing unseen.
Source: Edible mushroom