URDF
URDF (Unified Robot Description Format) is used to describe a robot’s structure, geometry, and physical properties for use in ROS. This article introduces URDF and provides a set of tutorials for building, extending, and using robot description files.
URDF (Unified Robot Description Format) is a file format for specifying the geometry and organization of robots in ROS. A URDF file follows the XML format as described on here.