Why did scientists call the period of history in which the most ancient people lived the Stone Age?

The Stone Age covers the time period at the end of the Late Paleolithic (18-7 thousand years BC). This period received this name due to the fact that people then made most of the tools and everyday life from stone. Some scientists call most of the small devices made of stone microliths, which characterize the period in which they were created. During the Stone Age, the Neolithic Revolution took place, which radically changed the further course of human development.