XML stands for Extensible Markup Language that is similar to HTML but different in using tags for defining objects. The whole idea behind creation of XML file format was to store and transport data without being dependent on software or hardware tools. Its popularity is due to it being both human as well as machine readable. This enables it to create common data protocols in the form of objects to be stored and shared over network such as World Wide Web (WWW).
You can also search many other file formats. Please see the complete list below.