When installing an pkg game is only done extract files ?

Hello.
When trying install an game using pkg install which tasks are done by RPCS3 ?
Only extract the in /dev_hdd0/game/ or does more others tasks as register game installation ?
In the console when is installed an pkg game is only done an extract or does any register or written in PS3 OS database ?
I only want understand if using RPCS3 in XMB mode is better install pkg games using in the XMB instead RPCS3 interface.

Thanks for reading my topic.