What are the HTML DOCTYPE, and what are their differences and uses?

Developed based on standard Generalized Markup Language (SGML), the DTD needs to be referenced, and the HTML5 based on XML development is not needed! DOCTYPE to standardize the behavior of the browser.

HTML 5

<! DOCTYPE html>

HTML 4.01 Strict

<! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01//en" "HTTP://WWW.W3.ORG/TR/HTML4/STRICT.DTD" >

(The DTD contains all the HTML elements and attributes, but does not include both the display and deprecated elements, such as font.) Frameset not allowed (framesets))

HTML 4.01 Transitional

<! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" "HTTP://WWW.W3.ORG/TR/HTML4/LOOSE.DTD" >

(The DTD contains all the HTML elements and attributes, including display and deprecated elements such as font.) Frameset (framesets) is not allowed. ）

HTML 4.01 Frameset

<! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 frameset//en" "HTTP://WWW.W3.ORG/TR/HTML4/FRAMESET.DTD" >

(This DTD is equivalent to HTML 4.01 transitional, but allows frameset content.) ）

XHTML 1.0 Strict

<! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 strict//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd" >

(DTDs contain all HTML elements and attributes, but do not include both display and deprecated elements, such as font.) Frameset (framesets) is not allowed. The notation must be written in well-formed XML. ）

XHTML 1.0 Transitional

<! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">

(The DTD contains all the HTML elements and attributes, including display and deprecated elements such as font.) Frameset (framesets) is not allowed. tags must be written in well-formed XML. ）

XHTML 1.0 Frameset

<! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 frameset//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd" >

(This DTD equates to XHTML 1.0 transitional, but allows frameset content.) ）

XHTML 1.1

<! DOCTYPE HTML PUBLIC "-//w3c//dtd XHTML 1.1//en" "Http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd" >

(This DTD is equivalent to XHTML 1.0 Strict, but allows models to be added (for example, to provide Ruby support for East Asian languages). ）

What are the HTML DOCTYPE, and what are their differences and uses?