"Classic Mode" is not a fully boot-capable system onto itself...
As such it relies heavily on a host Mac OS X 10.4(.11) to work
and its sole purpose in the configuration so intended is to run
older Mac system software, that otherwise would not run on
the later hardware, in the later modern operating system.
Those models who were older, yet could be upgraded to Tiger
OS X 10.4(.11) can {if original software disc with System 9.1/.2}
were included, would still be able to dual-boot and see the full
and real earlier Mac OS pre-X system, as a complete system.
The control panels and other parts of original system 9.2/9.1
aren't activated when Tiger OS X 10.4.11 'sees' Classic Mode.
I've had a few (dozen) Macs that dual-boot older/newer systems.
But Classic Mode itself, in the last incarnate which is not supported
by OS X 10.5.8 Leopard (due to hardware change) was to allow a
transition Mac to still access earlier pre-X applications in then/new
hardware. This was done to allow invested users of older software
a chance to later upgrade their software to newer OS X applications.
And some confusion exists even now, when some have not fully
explained the original situation, and/or interchanged terms when
they actually have different meaning. "Classic" prior to OS X was
more likely to apply to an early model all-in-one Macintosh, than
to a pre-X system. The advent of later OS X and reference to the
before system 10 system and applications, led to another meaning.
And so did the lapse of Mac hardware ability to start up in pre-X
operating systems, which could not natively run older Mac apps.
"Classic" is not "Classic Mode", much like neither of these is a
vintage collectable all-in-one Macintosh pre-G 68000 CPU.
Suggested reading may include some pages on wikipedia site.
Good luck & happy computing! 🙂