说明：  XML代表Extensible Markup Language（eXtensible Markup Language的缩写，意为可扩展的标记语言）。 与HTML相似，XML是一种显示数据的标记语言，它能使数据通过网络无障碍地进行传输，并显示在用户的浏 览器上。XML是一套定义语义标记的规则，这些标记将文档分成许多部件并对这些部件加以标识。它也是元 标记语言，即定义了用于定义其他与特定领域有关的、语义的、结构化的标记语言的句法语言。
(XML behalf of Extensible Markup Language (eXtensible Markup Language of the acronym meaning extensible markup language). Similar with HTML, XML is a markup language to display the data, which enables data to be transmitted through the network accessible and displayed in the user' s browser. XML is a set of rules that define the semantics of tags, these tags will be divided into many parts of the document and to identify these parts. It is also the meta-markup language that defines the specific areas used to define the other, semantic, structured markup language syntax language.)