Home is where the part is?

[JAZZCNC]

Bubba's kinda correct but really there's only 1 true HOME position and that's Machine Zero has designated by fixed switches.
All other positions are WORK offsets G54 G55 etc which have there own Zero point coordinate which is a 100% Known distance from Machine coordinate Zero.
Think of the complete machine work envelope(G53) has Machine coordinates area which has a fixed unmovable start point this can then be broke down into many individual work areas each having there own Zero start point using work offsets G54 etc.
This applies whether using offsets or not and Often G54 is the only offset used and it's zero position is the same has G53 machine zero coordinate for this reason G54 is used has default offset if no other offset is specified, so in this case G53 and G54 have the same Zero point.

On top of this there can be another Zero position known has a Local coordinate called using G52 which is a set distance from the current Work offset Zero position but won't go there has it's not often used unless using multiple fixture jigs in the same work offset.

So all this said then I'd have the HOME switches positioned to match Cartesian coordinate system relative to how your going to view the machine.
Then don't think of this Home position has WORK zero but absolute Machine zero. Work zero is any were choose on table start the cutting of the job with a known distance from MACHINE Zero.

The real beauty and point to having a 100% unmovable Home position is to use has cast iron reference point for getting back to exact WORK Zero position when job goes tits up.
The work offsets just designate a set point from Absolute(53) Machine coordinate position.

Home switches can and will save you hours of work when things go wrong but don't wreck the work. They allow you to quickly get back into exact position at any point on the work and start job again from that point.