What name do historians give the time after the stone age?

Immediately after the stone age came the copper age. A few hundred years after copper smelting began tin was discovered. Tin was mixed with copper and the bronze age began. About that time the early iron age also began.

10 men with bronze sWords could defeat 100 with early iron age sWords. Still, men with early iron age sWords could defeat men with stone weapons. Iron was far easier to get than bronze.