1. What is XHTML? HTML is a basic WEB web page design language. XHTML is a markup language based on XML. It looks somewhat similar to HTML, with only some small but important differences. XHTML is an XML that plays a role similar to HTML. So, in essence, XHTML is a transitional technology that combines the power of XML (somewhat) with the simplicity of HTML (mostly). At the end of 2000, the international W3C (World Wide Web Consortium) organization announced the release of XHTML version 1.0. XHTML 1.0 is a new language optimized and improved on the basis of HTML 4.0, aiming at XML-based applications. XHTML is an enhanced HTML, and its scalability and flexibility will adapt to more needs of future network applications. Below are answers to common basic questions about XHTML from Steven Pemberton, chairman of the W3C's HTML Working Group. Q:What is XHTML? Answer: XHTML is a kind of HTML reshaped to adapt to XML. When XML became more and more a trend, a question arose: If we have XML, do we still need HTML? In order to answer this question, we held a two-day working meeting in San Francisco in May 1998. The conclusion is: needed. We still need to use HTML. Because a large number of people are accustomed to using HTML as their design language, and millions of pages are already written in HTML. Question: Why did XHTML 1.0 develop independently from HTML 4.0? Answer: Not so. XHTML is exactly a reorganization of HTML 4.0 (to be precise, it is HTML 4.01, a modified version of HTML 4.0, but released under the name XHTML 1.0.) There will be some necessary differences in their interpretation in XML, but in addition On the one hand, they are still very similar, and we can think of the XHTML work as a continuation of HTML 4.0. Question: How does XHTML 1.0 implement the XML standard? Answer: XHTML is an XML application. It is defined in XML's DTD file format and runs on systems that support XML. Thanks to the Namespaces feature of XML, browser manufacturers do not need to create new private tags (tags). They only need to include XML code snippets in XHTML code, or XHTML code snippets in XML code. 2. What are the characteristics of XHTML compared with HTML? (1) XHTML solves the problems of HTML language that seriously restrict its development. There are three main shortcomings in the development of HTML today: it cannot adapt to the needs of more and more network devices and applications. For example, mobile phones, PDAs, and information appliances cannot directly display HTML; because the HTML code is not standardized and bloated, the browser needs to be smart enough and HTML can be displayed correctly only if it is complex; data and performance are mixed, so if your page needs to change the display, you must re-create the HTML. Therefore, HTML needs to develop to solve this problem, so W3C formulated XHTML. XHTML is a bridge from HTML to XML. (2) XML is the development trend of the web, so people are eager to join the XML trend. XHTML is the current standard that replaces HTML4 markup language. Using XHTML 1.0, as long as you carefully follow some simple rules, you can design a page that is suitable for both XML systems and most current HTML browsers. What this means is that you can design to use XML immediately without waiting for people to use XML-capable browsers. These guidelines can smooth the transition to XML on the web. (3) Another advantage of using XHTML is that it is very strict. The current bad situation of HTML on the Internet is shocking. Early browsers accepted private HTML tags, so people had to use various browsers to detect the page after the page was designed to see if it was compatible. There were often many inexplicable differences. , people had to modify the design to accommodate different browsers. (4) XHTML can interact well with other XML-based markup languages, applications and protocols. . (5)XHTML is part of the Web standards family and works well on other user agents such as wireless devices. (6) In terms of website design, XHTML can help you get rid of the bad habit of presentation layer code and help you develop the habit of tag verification to test the working of the page.