The two major differences between Chicago's Author-Date (AD) and Note-Bibliography style is that in AD style, "sources are cited in the text, usually in parentheses, by the author’s last (family) name, the publication date of the work cited, and a page number if needed." In addition, in the full reference list (called "References" or "Works Cited"), the year of the work's publication is the second element in the entry, directly following the author’s name.
Text Citation:
(Last-name Year)
Example:
(Woodward 1987)
Reference Entry:
Last-name, First-name. Year. Title of Work. Place of Publication: Publisher.
Example:
Woodward, David, ed. 1987. Art and Cartography: Six Historical Essays. Chicago: University of Chicago Press.