什么是XML Schema

XML Schema用来描述XML文档的结构，XML Schema也为XML文档，是DTD的替代品。其可以描述XML文档的元素、子元素的个数、子元素的顺序、元素的属性、数据类型等。

可以使用XPath来查询XML文档中的节点，其基于树的结构来表示XML文档。

 

XML Schema

XML schema describes the structure of the XML document. It is a XML-based alternative to DTD. It defines the elements, the number of child elements, the order of child elements, the attribute of the element, and data type.

XPath is a query language to select nodes from XML documents. It is based on a tree representation of the XML document.