udev (userspace /dev) is a device manager for the Linux kernel. It can be used for the following:
Add actions to the attachment/removal of certain devices.
Make devices available without root privileges.
Recognize older devices
Load UVC extension units.
The udev rules file is generated during the build step; the template is located at data/udev/
The default installation path is: /etc/udev/rules.d
For more information, refer to the man pages of udev (7,8).