The "publication date" refers to the specific day when a book, article, or other written work is made available to the public. This date is important because it helps readers know when the content was released and can indicate its relevance or timeliness. For example, a scientific study published in 2023 may provide more current information than one published in 2010. In the context of books, the publication date is often found on the copyright page, while for online articles, it is usually displayed at the top or bottom of the page. Knowing the publication date can help readers assess the credibility and context of the information presented.