HyperText Markup Language/Tag List/html

Use
wraps the whole HTML document. The opening tag is placed directly after the doctype declaration, the end tag at the end of the document.

It is recommended that the primary language of the document is indicated with either the   attribute for HTML or the   attribute for XHTML. XHTML 1.0 documents served with a MIME type of  should use both   and.

Example
An English language HTML 4.01 document.

An English language XHTML 1.0 document.

xmlns
In XHTML 1.0 and XHTML 1.1  is required. defines the XML namespace. Its value in XHTML 1.0 and XHTML 1.1 is.

Standard attributes

 * dir
 * lang
 * xml:lang

More info
The HTML element in HTML 4.01 Specification

The &lt;html&gt; tag on W3Schools