Html, html5, xhtml - what's the difference between them?

Question

should I learn all of them? or there's one better than the others?
Thanks in advance :)

Answer 1

Got it thank you! Rasheed what do you mean by saying "us"??

Answer 2

These are the improved version of HTML.
earlier HTML used now a days HTML5 used.xhtml is for graphical representation.
any queries msg us on what's app [phone]

Answer 3

These are versions of HTML. There are many features and new tags that are in HTML5 but not in old HTML and so on.