Citations are references used in academic and professional writing to give credit to the original sources of information, ideas, or research. They help readers locate the original materials and verify the information presented. Common citation styles include APA, MLA, and Chicago, each with specific rules for formatting. Using citations is essential to avoid plagiarism, which is the unethical practice of using someone else's work without proper acknowledgment. By citing sources, writers demonstrate their credibility and respect for the intellectual property of others, contributing to a culture of honesty and integrity in research and writing.