I made a Kubuntu Live USB, now I'm trying to figure out what the hell it does. It has a syslinux with gfxboot on it, so here I am, making a few page improvements as I go.
MBR -> syslinux with gfxboot -> boot LiveUSB that uses aufs to mount squashfs on a modifiable root. (??)
Truthfully, the best explanations of these are all on Wikipedia.