Different between HTML abd XHTML

Answer 1

XHTML (Extensible HyperText Markup Language) is a family of XML markup languages that mirror or extend versions of the widely used Hypertext Markup Language (HTML), the language in which web pages are written. Extended version of HTMLthat is stricter and XML-based.
Source - https://www.diffen.com/difference/HTML_vs_XHTML

Answer 2

what @qwerty said is spot on