On Windows hosts, a kernel mode device driver provides USB proxy support. It implements both a USB monitor, which enables to capture devices when they are plugged in, and a USB device driver to claim USB devices for a particular virtual machine. System reboots are not necessary after installing the driver. Also, you do not need to replug devices for to claim them.

On supported Linux hosts, accesses USB devices through special files in the file system. When is installed, these are made available to all users in the vboxusers system group. In order to be able to access USB from guest systems, make sure that you are a member of this group.