The description of xml format expansion
The xml file is an Extensible Markup Language document, which uses special tags in order to identify the objects and their attributes. The file is being formatted as an HTML-document. However, it applies exclusive tags for identification of the objects and data, which they contain.
The XML-document can be considered as a foundation of the database text. The XML-files have become the standard method of saving and transferring data between the apps and through the web. They can be edited in the basic text editor, as far as they are being formatted as text documents.