Xml
What is a standard language?
Hypertext Markup Language, the essence of HTML is "Markup)," Markup), "Method" is: Method for encoding data on the data itself (Elude: Yellow fluorescent The pen puts some sentences on the class, it is to set the statement.), All people follow the same set of standards as you (have you seen people who have been picking up unimportant texts?) In HTML, the tag is the so-called "tag".
A section of HTML code,
What is XML
Like HTML, Extensible Markup Language is also a marking language. The function is stronger than HTML, "people", and the powerful function of XML comes from "X". XML is not like HTML, providing a set of labels that have been defined in advance, but provides a standard that uses this standard, you can define your own new marking language according to actual needs, and set it for you. Language regulates a set of labels. Accurately, XML is a source labeling language.
Let us consider a very simple example. If we need to define a new marking language called TclMl (Topdigi Company S Client List Markup Language) - Topdigi's customer list marking language.
In order to let others understand these data, the standard standards in the marking language need to include:
Syntax
Each policy
In XML, the syntax of the marked is described by the file type definition DTD (Document Type Definition). That is, we describe what is a valid label through DTD to further define the structure of the marking language. In a marking language defined with XML, the DTD and data files are partially separated.
Tclml.dtd: In order to clarify the meaning of each tag, XML uses the style sheet connected to it ( STYLE SHEET, by it, provides an instructions for how to handle the display to the application, such as a browser. The specific format of a style sheet We are in detail in Chapter 4. Now we only need to know that the rules made by the style may be like this:
1. Whenever you see a tag. Similarly, Converts to a tag.
2. All
3. All
This shows that we must not only combine three files, but also create or purchase a new application handler. so horrible! These are worth it.
HTML has many crises
