Updaded Driver information please

[Robin Hood]

I would like to know what happens when you update drivers...Do you just ADD additional newer versions to the already existing driver, or do you get rid of the old drive and just replace it with a new driver? The reason why I'm asking this is, that if i have a driver "ver 1004"...and you update it to a "ver 1008"...can i add BOTH (version 1004 AND 1008) to my driverpack, or do i just need to use version 1008, as version 1004 is already EMBEDDED inside version 1008?

thanks folks