Game Folder String

Hello. I know this may be comon sense to some but I cannot find any information about it in the posts I read or search results from google. Maybe its because I dont understand what it is, so I am not searching for it correctly.

I followed this guide to copy Castlevania from my PC to ps3 hdd0 and made it successfully work. That was pretty easy.

Clarification Eboot Process

But what I dont understand is why was the folder /devhdd0/game/BLES01047/USRDIR/ suggested? I know its not a random folder. Is it like a game ID or serial number? I'd like to know more about this so I can continue trying to copy some more games to the internal hard drive. Thanks.

Update:

I guess why i am more puzzled is because i thought that folder was supposed to be the title id? But when i opened up the .sfo from that game rip, the title ID is BLUS-30339 and not BLES01047. Does it matter which folder we make and place it on?