XML, short for Extensible Markup Language, is a widely-used markup language for creating structured documents and exchanging data across different systems. It provides a flexible and self-descriptive format that allows users to define their own tags and organize data hierarchically. In the context of the KL program and TeamTV, XML is used as the export format for the statistical data recorded during sports matches. The XML file contains all the relevant information, such as player performance, team statistics, and game events, which can then be imported into TeamTV for further analysis.