XML

XML (Extensible Markup Language) is a general-purpose specification for creating custom markup languages.[1] It is classified as an extensible language, because it allows the user to define the mark-up elements. XML's purpose is to aid information systems in sharing structured data, especially via the Internet, [2] to encode documents, and to serialize data; in the last context, it compares with text-based serialization languages such as JSON, YAML, and S-Expressions. [3]