A primary source is a direct account or record from the period, place, or people who are the subject of the historian's study. A secondary source is an account written later in time—for example, a textbook article. Whether a source is considered to be primary or secondary depends on how it is being used. An opinion article about the holocaust written in 1972 would be a secondary source on the topic or period of the holocaust. However, on the topic of "evolving perspectives on the holocaust through the last half of the 20th century," it becomes a primary source. Neither is to be confused with first-, second-, or third-order sources.

There are many different types of sources. It is useful to employ terminology, or classifications, for sources as a means of facilitating discussion. However, you will doubtless find sources that fit into multiple categories, and possibly even some that call for the creation of a new category. This is quite acceptable. One arbitrary, but logical and useful, classification of sources might include:

Text Sources	Visual Sources	Auditory Sources

Text sources consist of published and unpublished documents. Published documents—articles, books, and so forth—are usually easier to find. However, unpublished notes, diaries, letters, memos and the like often provide wonderful insights as well, and should play a large role in helping us to learn about people and events in a way that has been less manipulated.

Visual sources consist of a multitude of portraits, photographs, and even physical artifacts—personal belongings, tokens from a battlefield, and the like. As the old saying goes, seeing is believing.

Auditory sources such as speeches, songs, debates, and other recordings shed light on emotions and cultural ideals like no other medium. Hearing it "straight from the horse's mouth" can have a very special ring.

For each type of source that you use in a report or paper, you should be very conscientious about citing certain pieces of information, just as you would for other resources that you cite in a research paper. There are a number of accepted styles, some more appropriate than others for particular subjects. The examples below illustrate a reference to the Hine photograph (visual source on the preceding page) in two styles often used in history and language arts. For other types of style requirements you may be assigned, consult your teacher for extra information.