Agricultural Revolution
The Neolithic\Agricultural Revolution occurred, as humans began transitioning from food gathering to food producing (agriculture). The revolution occurred because right when the last ice age ended, the ground became warm. Which in turn, increased vegetation across the planet and made the ground arable. In simpler terms, this time period is when people started to farm to get their food (the domestication of animals and plants was another factor that made farming possible), instead of hunting and gathering. Something that comes with farming is stability. So people of this era, transitioned from a nomadic lifestyle to living in permanent settlements, in order to farm.