What is the purpose of the <meta> tag in HTML?

The tag in HTML serves the essential function of providing metadata about the HTML document. Metadata refers to data that gives information about other data, and in the context of HTML, it includes details such as the document's character set, the author of the page, and the viewport settings for responsive design, among others. This information is not displayed on the page itself but is crucial for browsers and search engines to interpret the document correctly.

By utilizing the tag, web developers can enhance the performance of their websites through proper optimization for search engine results and ensure that the web page behaves as expected across different devices. This is vital for improving user experience and search engine visibility, which can significantly impact the effectiveness of a website.