To make it simple: handreg is a domain that hasn't been online before, newly created and registered for the first time (although technically it could have been used back in the past, just been dropped, but we simplify here) - It's something totally new.
Another way is buying or obtaining an already existing domain (ExpiredDomains.net, DropCatch, numerous auctions and marketplaces) - when one way or another you getting a domain that has been owned by someone else.
Name gets registered with the registrar exactly the same way in both cases, it's just a matter of how it was supplied to you.