The document discusses three periods of the Stone Age: Paleolithic, Mesolithic, and Neolithic. The Paleolithic period began 2.6 million years ago and was characterized by primitive stone tools and humans living in small bands who gathered plants and engaged in fishing and hunting. Toward the end of this period, people developed spiritual and religious beliefs. The Mesolithic period occurred between the Paleolithic and Neolithic, and was a transition time marked by the development of microlith stone tools. The Neolithic period saw the domestication of animals, permanent housing structures, and evidence of crop farming and cultivation between 10,200 BC to 4,500 BC, ending with the start of the Bronze Age.