Primary sources are documents, images or artifacts that provide firsthand testimony or direct evidence concerning an historical topic under research investigation. Primary sources are original documents created or experienced contemporaneously with the event being researched. Primary sources enable researchers to get as close as possible to what actually happened during an historical event or time period. 

A primary source provides direct or firsthand evidence about an event, object, person, or work of art. Primary sources provide the original materials on which other research is based and enable students and other researchers to get as close as possible to what actually happened during a particular event or time period.

Some examples of primary source formats include:

• archives and manuscript material
• photographs, audio recordings, video recordings, films
• journals, letters and diaries
• speeches
• scrapbooks
• published books, newspapers and magazine clippings published at the time
• government publications
• oral histories
• records of organizations
• autobiographies and memoirs
• printed ephemera
• artifacts, e.g. clothing, costumes, furniture
• research data, e.g. public opinion polls

Secondary sources are works that analyze, assess or interpret an historical event, era, or phenomenon, generally utilizing primary sources to do so. Secondary sources often offer a review or a critique. Secondary sources can include books, journal articles, speeches, reviews, research reports, and more. Generally speaking, secondary sources are written well after the events that are being researched. However, if an individual writes about events that he or she experienced first hand many years after that event occurred, it is still considered a primary source.

Some examples of secondary source formats include:

• textbooks
• journal articles
• criticisms
• commentaries
• encyclopedias