When using any outside materials in your papers or research assignments, you will need to cite your sources. This gives credit to the original authors of your sources, allows your reader to locate more information if they are interested, and allows you to avoid plagiarism.
Most citation styles will have an in-text citation which is a shortened citation in the body of your paper. Some styles may use footnotes for this instead. These in-text citations or footnotes will directly correspond to a full reference to the source you used at the end of the paper in a list. This list can be called a references list, a bibliography, or a works cited list, depending on the style.