A primary source is an immediate or up-to-date account of an incident or theme. It is the most direct evidence of an era or incident since it was created or written by people or things at the event or time. These sources have not been changed by clarification and provide new information or unique thoughts.
Primary sources are essential resources of historical research - they are the artifacts or documents closest to the study subject. Frequently they are formed throughout the time, which is being examined (journals, correspondence, government documents, newspapers, and art). However, they can also be created later by witnesses or contributors (oral histories and memoirs). Historians may discover primary sources in their simple format (typically within an archive) or replicate in a diversity of methods: digital, microfilm, books, etc.