On what did humans first leave traces of words?

About 1300 BC. Oracle Bone Inscriptions is an ancient writing carved on tortoise shells and animal bones. In Shang dynasty, the king had to do divination before doing anything. Oracle Bone Inscriptions is a tool for divination.

Long ago, people invented and used writing. The earliest scripts were produced more than 3000 years BC, such as T-shaped (cuneiform) in the two river basins and sacred script (hieroglyphics) in the Nile basin. Oracle Bone Inscriptions in Xia and Shang Dynasties from 65438 BC to 0300 BC was recognized as the earliest Chinese character, but recent new research shows that the history of China's writing should be pushed forward, and Wen Tao unearthed from Banpo site is the earliest Chinese character. In this way, the history of China characters can be pushed forward to 2500 BC.