A "source" refers to the origin or starting point of information, materials, or resources. In research, a source can be a book, article, website, or any document that provides data or insights. It is essential for verifying facts and supporting arguments in academic and professional work. In journalism, a source can also refer to a person or organization that provides information to reporters. These sources can be official, like government agencies, or unofficial, such as anonymous whistleblowers. Reliable sources are crucial for ensuring the accuracy and credibility of news stories and reports.