A "Reference" is a source of information that provides context or support for a statement or idea. It can include books, articles, websites, or other materials that help validate claims or provide further details. References are essential in academic and professional writing to ensure credibility and allow readers to verify information. In research, proper referencing is crucial to avoid plagiarism and give credit to original authors. Common referencing styles include APA, MLA, and Chicago, each with specific rules for formatting citations. Using references effectively enhances the quality of work and demonstrates thorough research.