Chicago Style is published by the University of Chicago.
"Chicago-style source citations come in two varieties: (1) notes and bibliography and (2) author-date. The notes and bibliography system is preferred by many working in the humanities—including literature, history, and the arts. In this system, sources are cited in numbered footnotes or endnotes. The author-date system is more common in the sciences and social sciences. In this system, sources are briefly cited in the text, usually in parentheses, by author’s last name and year of publication." (The Chicago Manual of Style Online, 2017).
You can find more information about Chicago format and citation style at the links below.
The Chicago Manual of Style can be used for most fields of study because it has two methods of citation creation -- the 'Notes and Bibliography' method and the 'Author-Date' method.
The Notes and Bibliography method is most often used by those in the humanities (history, literature, the arts, etc.). In-text citations for the Notes and Bibliography method use footnotes or endnotes which correspond to a number in the text.[1]The footnote or endnote includes a citation of the source and sometimes a note about the item cited. A footnote or endnote can be used for paraphrasing or direct quotes. If you use a source repeatedly, you would should put a full bibliographic citation of the source in the first footnote/endnote and a "shortened note" in subsequent footnotes/endnotes.[2]
[1] "Chicago-Style Citation Quick Guide," The Chicago Manual of Style, 2017. Most word processors have footnotes or endnotes ready to be inserted and already formatted correctly -- if you're having trouble figuring out formatting, reach out to a librarian.
[2] "Chicago-Style Citation Quick Guide" 2017.
The Author-Date method is most often used by those in the sciences or social sciences (biology, sociology, etc.). In-text citations for the Author-Date method uses parenthetical citations with the author's last name and year of publication and the page number when applicable (typically when there is a direct quote).