coolair or ram air

ok im new so bare with me.....

what is ram air intake?
how is it diferent from coolair?
whats the pros and cons for both?

Ram air = car moving air goes directly into air filter
Cool air = air filter outside of engine bay
Cool ram air = air filter outside engine bay sucking cold air in from moving car (hint hint... cold air intake and cut hole in bumper in front of it)