Citations are used to acknowledge the sources of information you are using. They give credit where credit is due. In addition to avoiding plagiarism and demonstrating how your writing builds upon previous work, citations help you meaningfully engage in academic discourse. They also help enhance the credibility of your writing.
Source: A (Very) Brief Introduction. This video provides a short introduction to how and when to use citations. Created by NCSU Libraries under a Creative Commons 3.0 BY-NC-SA US license via YouTube.
Citations
Describe books, journal articles, websites, or other published items
Give credit to the originator of an idea, thus preventing plagiarism
Enable the reader to retrieve the item you refer to
Include the author, title, date, source, and DOI if available