Updating PSP games?

Hi

I just updated killzone: liberation. on my psp, however the updates are still present on my memory stick under the GAME > MEMORY STICK, library..

I was wondering: Since I have already installed these updates, may I now be able to delete them off my memory stick? Or must they remain present on the memory stick in order to keep the game updated?

Your help is much appreciated :)

Cheers

ohhh ok. And this is the same for every game?

+thank you for the help dude :)