All my apps and games not work

all my apps including game suddenly frozen and none of them work. i restart iphone but it does not work either. does any one know what happen?

Is your phone jailbroken? Have you tried resetting your iPhone via iTunes? Did you do or install anything new when this happened?

my phone is not jailbreak. after playing game for a while, the game suddenly shut down and i am unable re-open but. it happen with every application in the phone except the factory apps such as camera, photos or itune store...

Restore it via iTunes.

whenever i tried to download an application it appear:
"unknown error occurred (-9808)"
what is that mean and how can i fix it?

it indicate below that this is an itune store error.