[Samba] Use "wbinfo" to create local user/group, but where is the account ?

[Iap, Singuan]

wbinfo has several options on managing the local user/group accounts.
But these accounts seem
               not system account (/etc/passwd), 
               not smbpasswd managed accounts , 
               not remote ADS accounts. (via winbindd)
What are those acccounts for?

Any hints are very appreciated.

Iap