Primary sources are first-hand, original documents that are closest to the source material. In historical research, primary documents are examined and pieced together to form conclusions about historical events. Primary documents include newspaper articles (from the time of the historical event), diaries, autobiographies, photographs, or any other source of information that was created at the time being studied.
Secondary sources are written after a historical event, and often reference primary sources. They may cover the same topic as a primary source, but include a layer of commentary, interpretation, and analysis. Secondary sources may provide a more balanced treatment of historical events since they can take into account varying points of view. Secondary sources include articles written for scholarly or popular publications, books, and films.
When you research in the field of history, it is important to use both primary and secondary sources.