Refcard: XML

XML  is a general-purpose specification for creating custom
mark-up languages. It is classified as an extensible language
because it allows its users to define their own elements. Its
primary purpose is to help information systems share structured
data, particularly via the Internet, and it is used both to encode
documents and to serialize data. In the latter context, it is
comparable with other text-based serialization languages such
as JSON and YAML.
As a diverse platform, Java has several solutions for working
with XML. This refcard provides developers a concise overview
of the different xml processing technologies in Java, and a use
case of each technology.

Get it here: xml