[Libvir] Difference between API functions virConnectNumOfDefinedDomains and virConnectNumOfDomains

Hello libvirt fellows, I have some problems to distinguish between those function calls in libvirt API:

virConnectNumOfDefinedDomains virConnectNumOfDomains

The API description states on both function that they will return me the number of active domain. Am I right if I assume that the first function virConnectNumOfDefinedDomains returns me all defined, but necessarily not running domains, and the second one only running and therefore active domains? Can you please help me and clarify this? Didn't had the chance to test this so far. But I will do so asap. Maybe the API documentation has to be updated in this point. Cheers, Jan