Anthony,
I assume you are talking about workspace offsets. I use WinCNC and G54 is default. I might use G55 for a second vertical head, a pen, a laser or maybe just a special fixture mounted someplace on the machine. After a call for G55, my new X, Y, Z zeros line up my other item. All I have to do is call G54 and my workspace shifts back to my default. The rest would be more workspace offsets. I hope this helps you understand.
Your controller might be different. I'm not familiar with it. Sorry.
From Wikipedia - "..butter knife..any table knife designed with a dull edge and rounded point". I've never claimed to be the sharpest knife in the drawer!