What are meta tags?
Meta tag is a tag, that contains information about a website and it is usually shown in the header of the web page. This information is used by search engines in order to show a web page title and description in their search results.
Meta tags are written in HTML code and they are not visible to external visitors. Visitors see just a page title and description of a web page that was indexed. If meta tags are well-written, they can increase the PageRank.