If you include information in your paper that is not original to you -- whether it's directly quoted or paraphrased -- you must include an in-text citation that corresponds to an entry on your Works Cited page! Usually it's the author's last name that bridges this gap.
APA refers to a set of editorial style guidelines overseen by the American Psychological Association. As with other styles, it is used by publishers to ensure standard writing and citations to increase the ease of readability. APA Style is typically used in the social and behavioral sciences. Read more about it.
The APA-style research paper contains a title page, an abstract, the body of the paper, and references: the shortest paper possible using full APA style will be 4 pages long. Each page contains a running head with page numbers.
There are two steps to creating a proper citation: the list of references at the end of the paper and the in-text citations. The in-text citation is where you give immediate credit for the work you are using. In-text citations help connect your reader to the information you've included to your references.
In APA style, in-text citations follow this basic format:
(Lastname, year, p. #) e.g., (Smith, 2013, p.14)
In that example, the reader would know to flip to your References page and skim down the left margin until they saw "Smith," and there they would find the rest of the publication details to track down that same source for themselves.