drv8825: fault vs enable vs sleep?

end goal is a tank-bot (2 steppers drive tracks). 2 steppers, drv8825s, and my solution to the 'simultaneous stepping' issue by just having one pin output to both step pins, and having the fault pin toggle which motor was enabled individually, and leaving their direction pins seperate. my question is: is there any difference between using fault, sleep, or enable? i read something saying that fault and sleep are tied together internally but fault was meant to be an OUTPUT from the driver board to signal a fault and that sleep was its input for that purpose. also apparantly enable would do the same thing-ish? its internally pulled to ground and will disable the chip if it gets pulled high.

tl:dr= for turning 8825 on/off, should i use enable, fault, or sleep? does it matter?