If it's off it means that apps cannot request to allow tracking. The default in this case is to outright disallow it for any app requesting. If the option is

If it's off it means that apps cannot request to allow tracking. The default in this case is to outright disallow it for any app requesting. If the option is on then the app can ask, and the user has a choice to allow or disallow. Again, if it's off, the default is to disallow tracking.