i'm not a logic user, but you definitely don't want your samples on your boot drive.
i'm sure you can choose to put them on a different drive, though someone else would have to tell you how if you're not sure.....
edit: and oh yea, like bass108 said, audio file typically refers to what your recording and samples refers to virtual instrument stuff.
yeh, i've had clicks/pops issues in the past by locating the samples on the boot drive, so thought it would be sensible having them on another internal hd.