In short, an HTML Meta Tag is a form of data tag that is placed between the open and closing head tags in an HTML web page. This information, though not visible on your web page itself, communicates to browsers and search engines certain details about your web page.
META tags have been used to communicate page information such as page title, description, keywords, as well as other specialized details such as web crawler instructions, language translation, and content information.
META tags used to be a very critical factor in SEO (Search Engine Optimization) but have lost some of their overall power. Check out our related blog on the effectiveness of using META tags for SEO purposes.