Primary sources provide first-hand testimony or direct evidence concerning a topic under investigation. They are created by witnesses or recorders who experienced the events or conditions being documented. Often these sources are created at the time when the events or conditions are occurring, but primary sources can also include autobiographies, memoirs, and oral histories recorded later. Primary sources are characterized by their content, regardless of whether they are available in original format, in microfilm/microfiche, in digital format, or in published format. A government's documents are direct evidence of its activities, functions, and policies. For any research that relates to the workings of governments, government documents are indispensable primary sources.
For decades the U.S. government has been the largest publisher in the world but government documents are also produced by regional, state and local governments and by international bodies such as the United Nations and the European Union.