Why use Metadata in HTML?

Metadata is a series of micro-communications between a site and search engines.

Nearly all metadata is invisible to visitors. It lives and works behind the scenes in the HTML of web pages. The metadata we use most for SEO speaks to search engines directly from each page crawled, to communicate important information or request specific action.

<meta> attributes and its values

• charset: It specifies the character encoding for the HTML document. Common values: UTF-8 (Character encoding for Unicode) and ISO-8859–1 (Character encoding for the Latin alphabet).
• content: It specifies the value associated with the http-equiv or name attribute.
• http-equiv: It provides an HTTP header for the information/value of the content attribute. It can be used to simulate an HTTP response header. Common values: content-security-policy (Specifies a content policy for the document), content-type (Specifies the character encoding for the document), default-style (Specified the preferred style sheet to use), and refresh (Defines a time interval for the document to refresh itself).
• name: It specifies a name for the metadata. Common values: application-name (Specifies the name of the Web application that the page represents), author (Specifies the name of the author of the document), description (Specifies a description of the page), generator (Specifies one of the software packages used to generate the document), keywords (Specifies a comma-separated list of keywords — relevant to the page), and viewport (Controls the viewport i.e. the user’s visible area of a web page).