When was writing invented?

Writing was invented independently in a handful of places, but the earliest known system is Sumerian cuneiform from southern Mesopotamia, dating to about 3400 to 3200 BCE. It began as pictographs pressed into clay tablets to record trade, taxes, and stores of grain, then evolved into wedge-shaped signs made with a reed stylus. Egyptian hieroglyphs appeared around the same period, and writing later arose separately in China and Mesoamerica. The invention marks the boundary between prehistory and recorded history, because for the first time people could store information across time and distance.