What are primary sources?
Primary sources are materials which provide first-hand evidence of an event, a person's life, or a historical period.
Letters, diaries, and oral histories are common types. These documents are like a scientist's raw laboratory data. They have not been edited or interpreted by a historian.
Secondary sources provide interpretations. Magazine articles, textbooks, and film documentaries are common types.
Secondary sources are likely to have quotations or sound bites from primary sources embedded in them. But, the overall product has been shaped to tell a certain story or prove a certain point.