Question

why do we try and divide history into different period

Answer 1

we divide it because we can sort events differently also it helps to keep a year wise record of events It is a systematic method so that we dont get confused for example its is divided asAD (annodomini) and BC (beforechrist)

Answer 2

we divide history into different period because of the voluminous nature of the historical event and so that it can be made easy for studies and to study them according to periodization and at the time when the event take place