Why two dots in myrobot.urdf.xacro filename

Course Support URDF for Robot Modeling
1

@staff
Below code is from URDF course

<param name="robot_description"
  command="$(find xacro)/xacro '$(find my_robot_description)/robots/myrobot.urdf.xacro'" />

Here we have the extension myrobot.urdf.xacro', i see that there are two dots here, one between myrobot and urdf and the other between urdf and xacro. The dot between urdf and xacro seems straightforward. I want to know if the dot between myrobot and urdf has any significance or is it treated as part of the filename?

2

It is treated as part of the file name.