Why are secondary sources important to the study of history?

All the information gathered by the person after the event has happened for example A history textbook is a secondary source.

Explanation:

A secondary source describes, analyzes and tries to make sense from the primary source.These may carry pictures, Graphics or quotes of the primary source.A secondary source analyzes and interprets primary source more effectively for example by interpreting or review of the previous finding of the magazine or articles and any history book or the texts on World War I Or II.That evidence or records which are come from the primary or original source are secondary sources.

He opposed the ideas of the enlightenment and liberal changes his entire life.