我想搞清楚咩叫primary source同埋secondary source,唔該

primary source 係一些沒經任何人修改過的一樣東西
secondary source 就被人加左些個人感想,修改原來的資料等


一些書籍等=secondary source
文物等=primary source

Primary sources
-things that come from the time a historian is studying.
e.g.
1. ancient buildings
2. photos

Secondary sources
-things that don't come from the time a historian is studying.
e.g.
1. magazines
2. biography