Configure description based upon OS environment

[SeanAlling-DojoFive]

In the net_lwip_webserver example there is the following in usb_descriptors.c

// Configuration array: RNDIS and CDC-ECM
// - Windows only works with RNDIS
// - MacOS only works with CDC-ECM
// - Linux will work on both
static uint8_t const * const configuration_arr[2] =
{
#if CFG_TUD_ECM_RNDIS
  [CONFIG_ID_RNDIS] = rndis_configuration,
  [CONFIG_ID_ECM  ] = ecm_configuration
#else
  [CONFIG_ID_NCM  ] = ncm_configuration
#endif

How can Windows, Linux, or MacOS select the right driver? For example if on Windows. RNDIS descriptor should be used whereas for MacOS CDC-ECM should be used.

Testing a device on both MacOS and Windows the correct descriptor is used, but I am unsure how TinyUSB was informed which descriptor to use.