Primary sources are records or documents created at the time historical events occurred. Primary sources could also be made after historical events have taken place by someone who participated in those events (for example, memoirs or oral histories). Some of the most common types of primary sources are letters, manuscripts, diaries, newspapers, statistics, interviews, memoirs, oral histories, speeches, objects, or artifacts.
Secondary sources interpret or analyze an historical event. Most secondary sources are books with footnotes or endnotes, journal and magazine articles that analyze or interpret past events, biographies, book reviews, literary criticism, or recreations of artwork or artifacts.