search for: hall_j

I would like to request you Samba gurus , what is the significance of teh file " username-map " which currently is in /usr/local/samba/lib. I have tried the following entries: jhall = hall_j kamal = kamal root = root but i dont know what it does , now the question : Can i manage users with this file , i.e I just add entries to this file on the fly and the users will have access to the shares, and can i define shares here. My second question is in order for a NEW smb.conf to take effe...