XML stands for eXtensible Markup Language.XML is nothing more than a text file containing a single well-formed XML document.
It is a general-purpose markup language that can be used to describe just about anything. XML differs from other markup languages like SGML and HTML. It’s a kind of metalanguage. The structure of an XML document must follow certain rules, but the vocabulary used within that structure isn’t tied to any dictionary of terms.
A tree data structure is built of nodes, with each node having only one node connected above it, called a parent node. The sole exception to this rule is the root node, which has no parent node. Nodes can also have other nodes connected below; these are called child nodes. In addition, nodes that are on the same level as the same parent node are called children. The following image is a graphical representation of a tree data structure.
An XML Document as Text
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<employee><empid/><empname/></employee><employee> <empid/> <empname/> </employee>