What is the stone age?

The Stone age was a prehistoric period that lasted for millions of years and ended in and ended between 4,000 BC and 2,000 BC , with the advent of metalworking.  In this period, stone was widely used to make stone tools and weapons with an edge, a point, or a percussion surface. 
The Stone Age is the first period in the three-age system frequently used in archaeology to divide the timeline of human technological prehistory into functional periods, with the next two being the Bronze Age and the Iron Age, respectively. 
Though some simple metalworking of malleable metals, particularly the use of gold and copper for purposes of ornamentation, was known in the Stone Age, it is the melting and smelting of copper that marks the end of the Stone Age.
The Stone Age is also commonly divided into three distinct periods: Paleolithic era which is the earliest and most primitive; a transitional period with finer tools known as the Mesolithic era; and the final stage known as the Neolithic era. Neolithic peoples were the first to transition away from hunter-gatherer societies into the settled lifestyle of inhabiting towns and villages as agriculture became widespread.