What is a citation?
"A reference providing information about where a particular quotation, text, etc., is to be found..."
- Oxford English Dictionary Online, version March 2015
A citation informs a reader that material in your work, such as a quote, image or idea, came from another source.
Research and scholarship is built upon the work of earlier scholars. By citing, you acknowledge those scholars, and provide a pathway to their work, which allows readers to find your sources and consider the derivation of your ideas.
Citations establish your credibility as a serious scholar by providing evidence that you have considered the existing information on a topic.
Failure to cite, or citing improperly, is considered plagiarism.