That would be an Era
The Renaissance Age was th age after the Middle ages.
A couple of alternatives would be 'eons' or 'millenia'
Ages and ages and ages means a really long time.
Many people use the two phrases the same way. But as far as professional history writing goes, the Dark Ages was the Early Middle Ages (476-100).
The prehistory and history of humans are often classified by the tools and technology used at certain periods of time. The three main periods are the stone age, bronze age and iron age (they occurred...