Puffball is the generic name for a large group of edible mushrooms with similar characteristics. They come in many sizes and are usually spherical or globular in shape.
Puffballs are distinguished from other mushroom groups by the fact that they lack many of the features or characteristics that other common mushrooms possess. A puffball has no stem. It has no cap. And no external gills. All of the spores are produced inside of the fruiting body.
The most common way in which they release their spores is through impact; the external force of rain or falling debris landing upon them or of animals stepping on or brushing against them, thereby compressing and/or breaking the peridium; the protective layer that encloses the spore mass inside the fungus. When that happens, as the name puffball implies, the spores are ejected in a large puff.