Q: What is the difference between xml and html? How are they different?
A: Regarding the difference between XML and HTML, please refer to:
http://www.w3c.org/MarkUp/
http://www.w3c.org/ XML/
“Extensible Markup Language” (XML) provides a way to describe structured data. Unlike HTML tags, which are used primarily to control the display and appearance of data, the XML tag is used to define the structure and data type of the data itself.
XML uses a set of tags to describe data elements. Each element encapsulates data that may be very simple or very complex. You can define an unlimited set of XML tags. For example, you can define some XML tags to declare data in the order, such as price, tax, shipping address, billing address, etc. Because the XML tag is adopted throughout and across organizations, data from a variety of different data stores will be easier to exchange and manipulate.
XML is a simple, platform-independent and widely adopted standard. The advantage of XML over HTML is that it separates the user interface from the structured data. This separation of data and display makes it possible to integrate data from different sources. Customer information, orders, research results, bill payments, medical records, directory data and other information can be converted to XML.
XML and HTML
Here are a few points to remember about the relationship between XML and HTML:
a. . XML is not meant to replace HTML; in fact, XML can be seen as a complement to HTML. XML and HTML have different goals: HTML is designed to display data and focuses on the appearance of the data, while XML is designed to describe data and focuses on the content of the data.
b.. Similar to HTML, XML does nothing. While the XML tag can be used to describe the structure of an item such as an order, it does not contain any code that can be used to send or process that order and ensure delivery on that order. Someone else has to write code to actually perform these operations on data in XML format.
c. Unlike HTML, the XML tag is defined by the schema or document author and is unlimited. HTML tags are predefined; HTML authors can only use tags supported by the current HTML standard.
Usage of XML
XML is an extremely flexible way to transfer data. The following are all examples of situations where XML can be used:
a.. Ordinary documents
b.. Structured records, such as appointment records or orders
c.. The Internet for mobile data /Intranet Web Application
d.. Objects with data, such as persistent formats for objects or ActiveX controls
e.. Data records, such as the result set of a query
f.. Meta content of a Web site , such as "Channel Definition Format" (CDF)
g.. Graphical display, such as the user interface of an application
h.. Links to information and people on the Web
i.. C# code (can be used XML form); for more information, see the XML Documentation
j.. Discovery documentation for locating available XML web services; for more For information, see XML Web services discovery.
Listed below are several advantages of XML over other formats when storing information:
a.. XML formats are text-based, which makes them easier to read. , easier to record, and sometimes easier to debug.
b.. XML documents can use much of the infrastructure already established for HTML, including the HTTP protocol and some browsers. HTTP allows transmission of XML through firewalls.
c.. XML parsing is well defined and widely used, making it possible to retrieve information from XML documents in a variety of environments.
d. Applications can rely on the XML parser for some structural validation and data type checking (when using schemas).
e.. XML is built on Unicode, making it easier to create international documents. However, XML is not suitable for every situation. XML documents tend to be more detailed than the binary formats they replace. They take up more network bandwidth and storage space, or require more processor time to compress. XML parsing may be slower than parsing highly optimized binary formats and may require more memory. However, careful application design can
avoid some problems.
Validate XML document
To verify that an XML document contains the required data and structure, a XML schema must be Associated with the XML document. The XML schema is the rules that define how elements and attributes are structured to form an XML document. You can share schemas between units to make it easy to transfer and process shared data. For more information, see XML Schema Introduction.
Displaying XML data
There are several ways to display (or provide) XML data.
There is also a data binding mechanism that can be used with style sheets to display XML data in a visual form and to add interactivity.
Here are several ways to display XML:
a.. Internet Explorer
For more information, see the MSDN Online
XML
Developer Center Web site (http://msdn.microsoft.com/xml/default.asp).
XML
Resources If you are familiar with HTML, you can learn to create XML
documents, as long as they are valid and conform to a standard format. For more information about XML
, see the XML SDK and MSDN Online XML Developer Center Web site (http://msdn .microsoft.com/xml/default.asp). For more information, see the World Wide Web Consortium (W3C)'s
XML
specification (http://www.w3.org/XML
/). Q: Then why do many large websites still use html instead of xml?
A:
XML
and HTML are essentially different. You said that large sites use HTML. If it is static data, HTML is of course the fastest, but it is not well maintained! Generally, XML
CSS is used for website design, but XML CSS has great limitations. It is better to use XML XSLT Q: Now I develop a website directly using xml, and then directly upload it to the ordinary static space provided now. Can it be displayed?
A: If it can be assumed that users all use (or at least have installed) IE6, there will be no problem.
If the user uses other browsers, they should perform
XML
->HTML conversion on the server side, which is not supported by ordinary static spaces. You can choose ASP or PHP space that supports XMLDOM. So the operating environment is different.