用于标记电子文件使其具有结构性的标记语言，可以用来标记数据、定义数据类型，是一种允许用户对自己的标记语言进行定义的源语言。-Used to mark it with a structured electronic document markup language, can be used to tag data, define data types, is a technology that allows users to define their own markup language sou