Whenever you use information from an outside source, you should provide a citation. You should cite both direct quotations and paraphrasing of ideas and concepts that aren't your own. This is done for a number of reasons:
1. It gives credit to the original author/creator of a work, an idea, or a concept. Anything that is published in a source like a magazine, newspaper, blog post, social media post, book, or journal is the intellectual property of the author/creator. This means that the author/creator owns the content and ideas that are published. Any reproduction of that content without proper attribution (citation) is considered plagiarism.
2. It allows your readers to trace your research and locate additional sources. This is how instructors verify that you've properly attributed thoughts and ideas that don't belong to you.
For more information on why you should cite your sources and a more in-depth explanation of plagiarism, see the Undergraduate Library's Citing Sources LibGuide. This LibGuide also provides general guidelines for citations in APA, MLA, and Chicago Style.