A Debian Live system CD is a Debian operating system preinstalled in some way, that does not require a classical installer to be used. It comes on media, like a cdrom, a usb-stick, or over a network.
In operation, it will require a boot process and hardware discovery (the same as Debian Installer), to launch a preinstalled rootfs.
This is mainly focused on debian etch gnome Live CD applications and desktop screenshots.[thumb:250:c:l=g]