When to cite
Whenever you use information created by someone else, whether you use their exact words or refer to their ideas, you need to give the creator(s) credit. Simply changing a word or two does not make the idea your own. Giving credit to the other writers or speakers whose ideas have influenced yours makes your own work stronger.
How to cite
There are two components to citing your sources: the in-text portion of the citation that identifies an idea as someone else's, and the list of works cited (also called a bibiliography) that helps your readers find the materials you cited. In order make your citations very clear you should use a standardized citation format. Two of the most common formats are the Modern Language Association (MLA) style and the American Psychological Association (APA) style. Using a standardized format helps your readers distinguish editions, page, issue, and volume numbers, and other key information included in a citation.