The <html> tag tells the browser that this is an HTML document.
The <html> tag represents the root of an HTML document.
The <html> tag is the container for all other HTML elements (except for the <!DOCTYPE> tag).
HTML5 has added a new attribute: manifest.
The xmlns attribute is required in XHTML, but is invalid in HTML.
However, the HTML validator at http://w3.org does not complain when the xmlns attribute is missing in an XHTML document. This is because the namespace "xmlns=http://www.w3.org/1999/xhtml" is default, and will be added to the <html> tag even if you do not include it.
Attribute | Value | Description |
---|---|---|
manifest | URL | Specifies the address of the document's cache manifest (for offline browsing) |
xmlns | http://www.w3.org/1999/xhtml | Specifies the XML namespace attribute (If you need your content to conform to XHTML) |