Xml html xhtml html5, xhtmlhtml5

Xml html xhtml html5, xhtmlhtml5

1. XML

What is XML?

• XML refers to the EXtensible Markup Language (EXtensible Markup Language)
• XML is a markup language, similar to HTML
• XML is designed to transmit data rather than display data.
• The XML tag is not predefined. You need to customize the tag.
• XML is designed to be self-descriptive.
• XML is W3C recommendation Standard

Main differences between XML and HTML

XML is not an alternative to HTML.

XML and HTML are designed for different purposes:

XML is designed to transmit and store data, with the focus on data content.

HTML is designed to display data. Its focus is on the appearance of the data.

HTML is designed to display information, while XML is designed to transmit information.

XML with no behavior

XML is not used.

This may be hard to understand, but XML won't do anything. XML is designed to structure, store, and transmit information.

The notes John wrote to George are stored as XML:

<note><to>George</to><from>John</from>
The above note is self-descriptive. It has the title and message, and contains the information of the sender and receiver.
However, this XML document has not done anything. It is just pure information encapsulated in XML tags. We need to write software or programs to send, receive, and display this document.
XML is only plain text
XML is nothing special. It is just plain text. Any software capable of processing plain text can process XML.
However, applications that can read XML can process XML tags in a targeted manner. The functional meaning of a tag depends on the characteristics of the application.
You can use XML to create your own tags.
The labels in the preceding example are not defined in any XML standards (such as <to> and <from> ). These tags were invented by the creator of the document.
This is because XML does not have predefined labels.
The tags used in HTML (and the HTML structure) are predefined. HTML documents only use tags defined in HTML standards (such as <p> and 
XML allows creators to define their own labels and their own document structures.
XML is not an alternative to HTML.
XML is a supplement to HTML.
XML does not replace HTML. It is important to understand this. In most web applications, XML is used to transmit data, while HTML is used to format and display data.
The best description of XML is:
XML is an information transmission tool independent of software and hardware.
XML is W3C recommendation Standard
The Extensible Markup Language (XML) became the W3C recommendation standard in February 10, 1998.
For more information about W3C XML activities, visit our W3C tutorial.
XML is ubiquitous
When we see the rapid development progress of the XML standard and the rapid adoption of this standard by a large number of software developers, we can't help but sigh that this is really amazing.
Currently, XML does not play a role in the Web as HTML, which is the cornerstone of the Web.
XML is ubiquitous. XML is the most common tool for data transmission between various applications, and is becoming increasingly popular in the field of information storage and description.
 
2. HTML
 
What is HTML?
 
HTML is a language used to describe web pages.
 

 

 
  
HTML refers to the hypertext markup language (HYperTExtMArkupLAnguage)
 
  
HTML is not a programming language, but a markup language)
 
  
A markup language is a set of markup tags)
 
  
HTML uses tag to describe Web pages

 
 
HTML Tag
HTML tag is usually called HTML tag ).

 

 
  
HTML tags are keywords surrounded by Angle brackets, such as  
  
HTML tags are usually paired, such as <B> and </B>.
 
  
The first tag in the tag pair is the start tag, and the second tag is the end tag.
 
  
The start and end labels are also known as open and closed labels.

 
 
HTML document = webpage

 

 
  
HTML document description webpage
 
  
HTML documents include HTML tags and plain text
 
  
HTML documents are also called Web pages

 
Web browsers read HTML documents and display them as webpages. The browser does not display HTML tags, but uses tags to explain the content of the page:
Example

  

 
   
Text description webpage between  
   
The text between <body> and </body> is visible on the page.
 
   
The text between  
   
The text between <p> and </p> is displayed as a paragraph

  
3. XHTML
 
 
What is XHTML?
 

  

 
   
XHTML refers to the Extensible hypertext markup language.
 
   
XHTML and HTML 4.01 are almost the same
 
   
XHTML is a more rigorous and pure HTML Version.
 
   
XHTML is HTML defined as an XML application.
 
   
XHTML is the W3C recommendation standard released in January 2001.
 
   
XHTML is supported by all mainstream browsers

  
 
Why use XHTML?
Many pages on the Internet contain "bad" HTML.
If you view it in a browser, the following HTML code runs normally (even if it does not comply with the HTML rules ):
XML is a markup language that must be correctly labeled and well-formatted.
If you want to learn XML, please read our XML tutorial.
Today's technology industry has some different browser technologies. Some of them run on computers, while others may run on mobile phones or other small devices. Small devices often lack the "bad" markup language resources and capabilities.
So-developed XHTML by combining the strengths of XML and HTML. XHTML is the HTML that is redesigned as XML.
The most important difference from HTML:
Document Structure

   

 
    
Xhtml doctype is mandatory
 
    
The XML namespace attribute in  
    
<Html>,  
   
Element syntax

   

 
    
XHTML elements must be correctly nested
 
    
XHTML elements must always be disabled
 
    
The XHTML element must be in lowercase.
 
    
The XHTML document must have a root element.

   
Attribute syntax

   

 
    
The XHTML attribute must be in lower case.
 
    
XHTML attribute values must be enclosed by quotation marks
 
    
It is also forbidden to minimize XHTML attributes.

   
 
<! DOCTYPE...> is mandatory
The XHTML document must be declared as An XHTML document type (xhtml doctype declaration ).
You can find the complete XHTML document type in the W3School label reference manual.
The 
The following example shows the XHTML document with the minimum required tags:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 
How to convert from HTML to XHTML
 
Test XHTML with W3C validators
Enter your URL in the text box below:
<!DOCTYPE HTML>