The fundamental difference between strict syntax in xhtml. Moreover, on=good xhtml page must begin with the xml Declaration. However, in this case at the slightest syntax error (e.g. unclosed input tag) will result in an error and the page will not be displayed.
Xhtml should not climb. This is a legacy specification. Modern VEB is guided in the direction of html5.
cortney.Kuhic answered on July 4th 19 at 23:45
No. XHTML is not necessary and, moreover, it is necessary to give with the MIME type "application/xhtml+xml". Only then the browser will process the document strictly as XHTML and not as HTML with "bat" layout (e.g. /> in HTML is impossible, so the parser ignores the slash as an error character and pass). In XHTML any error markup will lead to the results XML errors instead of the page.