A primary source
is any record contemporary to an event or time period. Primary sources may be written, oral, visual or physical. Some of these sources were produced with the intent of being preserved for the future. Such intentional sources
include government documents, church records, autobiographies or memoirs. On the other hand, many primary sources were produced without any intent of future use. Such unintentional sources
may include private correspondence not originally meant for posterity but which later are deposited in archives and libraries. Physical evidence such as buildings, clothing, tools, and landscapes may also be labeled as unintentional sources.
--Galgano, Michael J., J. Christopher Arndt, and Raymond M. Hyser. Doing History: Research and Writing in the Digital Age. Cengage Learning, 2007, p. 57.