Historical sources can be devided into three types.

Academic writing sources are the materials used by the writer to gather information about their subject. They are used to support arguments and theories given by historians and students of history. Materials used to study history can be classified into three types: primary, secondary and tertiary sources. Print sources, such as books or journals, are commonly used sources, but a source could also be recorded music or video, Internet sites or physical objects.

Primary Sources


Primary sources are contemporaneous to the subject being studied. They could be objects, letters, journal or newspapers. They must originate from the time being studied to be accepted as a primary source, this can include copied images of an original document, or reprinted editions of a book. If a historian was studying Abraham Lincoln, diaries and letters written by Lincoln would be primary sources.

Secondary Sources


Secondary sources are nearly always textual: books or journals. A secondary source would be an article written about a primary source. To continue the example above, an essay or book written about Abraham Lincoln based on his diaries and letters would be a secondary source.

Tertiary Sources


Tertiary sources are sources that rely on secondary sources for their information. This would include most school textbooks, essays written at school that cite textbooks and secondary sources. Books and essays that are historiographical in nature, so discuss the way in which history is presented, are tertiary sources.