I'm trying to understand /etc/mtab

[pogochris]

So about a week ago I picked up a pogoplug pink v2 as a little learning exercise after finding them for £20 at PCWorld and although its not my first venture into the Linux world it is by far the deepest. Normally I wouldn't go beyond setting up a simple web-server / asterisk box, but thanks to pogo I've ventured into the darker end of config files and compiling packages from source.

To my question, here is my mtab file:

$this->bbcode_second_pass_code('', 'rootfs / rootfs rw 0 0
/dev/root / ext2 rw,relatime,errors=continue,user_xattr 0 0
devtmpfs /dev devtmpfs rw,relatime,size=126652k,nr_inodes=31663,mode=755 0 0
proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0
/sys /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
/run /run tmpfs rw,nosuid,nodev,relatime,mode=755 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620 0 0
shm /dev/shm tmpfs rw,nosuid,nodev,relatime 0 0
tmpfs /tmp tmpfs rw,nosuid,nodev,relatime 0 0')

My question was going to be why does it look like / is mounted twice, but I have since discovered after a little searching that the first line is just there for the kernels benefit and just isn't shown usually (am I right?). My boggle is the second line, why is it /dev/root that's mounted and not /dev/sda1? It's not at all a problem but it bothers me not knowing.

I'm looking forward to lurking a bit more in these forums and learning more about Linux.