HTML META TAGS

Metadata is data (information) about data.
The meta tag provides metadata about the HTML document.
Metadata will not be displayed on the page, but will be machine-parseable.
Meta-elements are typically used to specify the page description, keywords, document author, last modification, and other metadata.
Metadata may be used by browsers (such as displaying content or page reloading), search engines (keywords), or other web services.
HTML5 introduced a method to allow web designers to take control over the viewport (the user-visible area of a web page), via the meta tag.

Here is an example of meta tags.