Citations are references used in academic and professional writing to acknowledge the sources of information, ideas, or data. They help readers locate the original materials and give credit to the authors or creators. Common citation styles include APA, MLA, and Chicago, each with specific rules for formatting. Using citations is essential for avoiding plagiarism, which is the unethical practice of presenting someone else's work as your own. Proper citations enhance the credibility of a piece by demonstrating thorough research and respect for intellectual property. They also allow readers to explore the topic further through the cited works.