XML stands for eXtensible Markup Language and it is a markup language used for encoding documents in a format that is both human-readable and machine-readable. XML is similar to HTML, but unlike HTML, XML does not have a set of predefined elements, attributes, or behaviors. Instead, XML allows users to define their own custom markup elements and attributes, making it a flexible format for representing structured data.XML is commonly used for exchanging data between different systems, for storing data in a structured format, and for creating other markup languages such as RSS, Atom, and XHTML. XML documents consist of elements, which can contain content and other elements, and are delimited by tags. The structure of an XML document is defined by a Document Type Definition (DTD) or an XML Schema, which specifies the rules for the document's structure and content.