Extensible Markup Language (XML) is a markup language that defines a set of rules for decoding documents in a format that is both human-readable and machine-readable. is used to describe data. The XML standard is a flexible way to create information formats and electronically share structured data via the public Internet, as well as via corporate networks.XML files are encoded for many important reasons, one of which to is done to protect the source code of web application, which is public (HTML, JavaScript, CSS) in order to be compiled by the browsers. The main point here is to protect our code from reverse engineering, tempering and stealing.