What are these "test" and "rpcs3_old" folders inside RPCS3 main directory?

"test" folder was only added in recent builds.

"rpcs3_old" folder gets created every time after updating RPCS3 and doesn't get deleted.

If we download a fresh RPCS3 build, there is only the "test" folder inside it, which means that at the very least "rpcs3_old" is a redundant folder that should not be there. Moreover, I tried removing them manually and the emulator seems to work fine which is also indicative of it that they are redundant folders only occupying space.

I would appreciate if someone could explain this.

test folder always existed but it was in dev_hdd0/game named as TEST12345.
This is technically wrong as it can conflict with homebrew that have serial ID as TEST12345 so it was moved out of the ps3 virtual HDD and renamed to test

rpcs3_old is a backup of the previous update in case there are any issues, you can restore the previous version from there

Ok, thanks for the explanation.