A person's diary? Or this specific one?
A person's diary helps us to learn about a different culture, by describing the day to day life of people living in that culture, as well as their ways of thinking which may be different from ours ( different morals, code of behavior, etiquette, etc. ). It details the day to day life, which could mean anything from different clothing, different food, different work, different familial roles, different traditions, different customs, etc.
