[Blind-sysadmins] file system setting on unattended xp cd

Hi everybody, what is the difference between iso 9660 only and iso 9660 + joliet. All info sources I've checked out say file system should be set to iso 9660, but when I listened to a rick harmon unattended xp creation podcast he said to use iso 9660 + joliet. I thought joliet was just a file naming convention. If I use iso 9660 only will it not work? Hope someone can help, John.