PRIMARY & SECONDARY SOURCES

A primary source is a document created during the time of the period under discussion.  Examples of primary documents include: letters, interviews, autobiographies, diaries, personal journals, and newspaper articles written at the time of the event under question.

Primary sources are invaluable for understanding a particular event because they are evidence of real time history (history in the making), at the moment it occurs.

A secondary source interprets or critiques knowledge based on primary sources.
Examples of such include most books and periodical articles, encyclopedia entries, etc.