XHTML
XHTML is a term that was historically used to describeHTML documents written to conform withXML syntax rules.
The following example shows an HTML document and corresponding "XHTML" document, and the accompanyingHTTPContent-Type headers they should be served with.
html
<!-- Content-Type: text/html --><!doctype html><html lang="en-US"> <head> <meta charset="utf-8" /> <title>HTML</title> </head> <body> <p>I am a HTML document</p> </body></html>xml
<!-- Content-Type: application/xhtml+xml --><?xml version="1.0" encoding="UTF-8"?><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US"> <head> <title>XHTML</title> </head> <body> <p>I am a XHTML document</p> </body></html>In practice, very few "XHTML" documents are served over the web with aContent-Type: application/xhtml+xml header. Instead, even though the documents are written to conform to XML syntax rules, they are served with aContent-Type: text/html header — so browsers parse those documents using HTML parsers rather than XML parsers.