Use of Meta and DTD

1. Whats the usage of <meta> tags
2. Why the DTD line is mentioned as the first line in all the web pages

HI

When authoring document is HTML or XHTML, it is important to add a Doctype declaration. DTD used for that

Metadata is information about data.

The <meta> tag provides metadata about the HTML document. Metadata will not be displayed on the page, but will be machine parsable.

Meta elements are typically used to specify page description, keywords, author of the document, last modified, and other metadata.

The <meta> tag always goes inside the head element.

The metadata can be used by browsers (how to display content or reload page), search engines (keywords), or other web services.

Regards