Although there are different citation formatting styles (e.g., MLA, APA, Chicago), most require you to cite your work in two places in a research paper.
First part in the body of the paper: At the place in your paper where you refer to the information from another source, you will need to place a reference to the source. For MLA or APA, this may be a short parenthetical citation, so-called because you need to put brief information (such as the author's name and page number with MLA style) in parentheses. For some styles, you may need to place a reference to a footnote or endnote.
Second part at the end of the paper: At the end of your paper, you should place the full source information in a list of works that may be called the References, Works Cited, or Bibliography. For this list, follow the formatting guidelines of your specific style.
Example: Transferring Information from Research Sources to Your Paper (MLA Style)