Dimmer is one possible use of an
address on the
console and vice versa. This is because the
console can use the
DMX address to control a
dimmer or any attribute on a device having them (Pan, Tilt on a mover, as example).
If you have a separate
circuit to
dimmer patch panel, then it's a separate patch and not dealt with at the
console.
The
Channel is the controlling function for the device at the
console -
dimmer or mover,
scroller,
etc.... Thus on the
screen you bring up
Channel 1 at Full, it may bring up any
dimmer patched to that
channel, or will allow manipulation of a device - moving the pan for a mover,
etc... via the
DMX addressing for that device.
EDIT: And as to the Patch by
Address vs
Channel, it's sometimes useful to be able to view the patch list by
address and if then needed, to patch an
address to a
channel and/or to simply view an
address. The Patch by
Channel view is useful for when you are using a printed
channel hookup to do a
manual patch, so
ETC gives it to you both ways.