The historian must be constantly and regularly looking for sources that enable his contact with historical events that have already taken place over time.
Historical events are opinions, thoughts, and social movements that have produced events and led to changes that have somehow impacted the life of a group or people.
To understand these events, the historian defines the aspects that he will study, the sources to be analyzed, the opinions he wishes to discuss and the feelings he deems most important.
The techniques, records, interviews, questions, data cataloging, among others, give security to carry out scientifically the work of the historian.
It should be remembered that no historical event is a 100% pure. The record of events always reflects, in one way or another, the opinion, thought and even the interests of the one who made notes about what he saw, lived or heard, but historians, when analyzing all the sources, must be as much objective as possible.