XML stands for Extensible Markup Language, which is a markup language and file format used for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. Unlike other programming languages, XML cannot perform computing. XML is a software- and hardware-independent tool for storing and transporting data. It is a textual data format with strong support via Unicode for different human languages. XML is widely used for the representation of arbitrary data structures such as those used in web services.

XML is designed to be self-descriptive and is concerned with how information is organized, not how it is displayed. XML lets you create your own tags to label the meaning or use of data, making it more flexible than HTML. XML formatting is done through separate style sheets. XML is used to describe the structure of data, while HTML is used to display data.

XML has come into common use for the interchange of data over the Internet. It is used for information exchange between computer systems such as websites, databases, and third-party applications. XML provides a way to store data in a format that can be stored, searched, and shared. XML is used for the serialization, i.e. storing, transmitting, and reconstructing arbitrary data. XML standardizes the process of exchanging information between disparate systems.

XML is used in many technologies, including newer ones, and comes with built-in support in many applications. XML is used for communication protocols such as SOAP and XMPP. It is the message exchange format for the Asynchronous JavaScript and XML (AJAX) programming technique. XML is used in many document formats, including RSS, Atom, Office Open XML, OpenDocument, SVG, COLLADA, and XHTML.

In summary, XML is a markup language and file format used for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. XML is widely used for the representation of arbitrary data structures such as those used in web services. It is designed to be self-descriptive and is concerned with how information is organized, not how it is displayed. XML is used for information exchange between computer systems such as websites, databases, and third-party applications. It is used in many technologies and comes with built-in support in many applications.