Most stepper motors are 1,8deg (200 full steps per revolution)
The driver can increase each full step into incremental partial steps like half step (1/2), quarter (1/4), eight step (1/8) etc. This is referred to micro stepping.
So I can have the same ACME, same stepper motor but I may have my motor driver set to half step and you 1/8.
I need 200 x 2 to make my motor turn one revolution, you on the other hand would require 1600.
If however we both had exact same settings, but my value would be 49.8 and you calibrated yours to 50.2 the difference will be due to measuring inaccuracy and/or system back lash (positional change during transition from one direction the opposite direction.