Chicago style is from the University of Chicago. Turabian style is based on Chicago style and was created to simplify the Chicago style.
There are two distinct methods (or systems) for citing sources in Chicago/Turabian style; be sure to choose the correct one:
Notes and Bibliography Style (also known as just notes or bibliographic or NB style): This is the preferred method for literature, history, and the arts. Sources are cited within your paper using footnotes and all sources are listed in a bibliography at the end of your paper.
Author-Date Style: This is the preferred method for natural, physical, and social sciences. Sources are cited in the text of your paper (called parenthetical references), with the author's last name and date of publication in parentheses, and all sources used are listed in a reference list at the end of the paper.
Note: A new version of the Chicago Manual (the 16th Edition) was just released. The Web sites listed in this guide are in the process of transitioning to the new formatting guidelines.