Citing your sources properly can help you avoid plagiarism. Plagiarism is when you purposefully or accidentally use someone else's words and/or ideas without giving them credit (AKA citing your source).
Northampton Community College's Academic Honesty Policy states that the penalties can include:
Chicago Manual of Style
What's the difference between references and in-text citations?
References belong at the end of your paper in a separate list sometimes known as a Works Cited page, bibliography, or reference list depending on the style you are using.
Example (APA style):
Click, P. (1994). Caring for school-age children. Albany, N.Y: Delmar Publishers.
In-text citations belong in the body of your paper. You will provide a citation after you mention each fact that you have found from a research source (article, book, website).
Example (APA style):
(Click, 1994)