m_yates handled the "root partition" well.
As for file systems, swap is used for just that: swap space. Anytime the OS needs more RAM than you have installed, it can use the swap prtition like (very slow) RAM. Other filesystems include:
- ext2 -- the old standard *nix filesystem.
- ext3 -- the "new" standard *nix filesystem. Basically it is ext2 with journaling added.
- ReiserFS - another journalling file system
- XFS, JFS, etc. -- more journalling file systems.
Most users use ext3, or Reiser, but the other systems have their niches.
RAID - Do you have a RAID system? I would assume that's why the option is present. (Which distro, by the way?)
BootLoader - This is what handles the bootup of your computer. It is very small, residing the the "boot sector" of your primary hard disk, and tells the computer what program(s) should be run when it boots. Windows XP uses "ntloader", a proprietary bootloader that can only boot into Windows (without some knowledge in how to change it). Linux uses lilo or grub, depending on the user's desire at installation. Both of these can handle any number of Linux distros *and* Windows easily.