Z offset (mm)

Z offset is the extruder Z offset relatively to the base point on a print head. If your printer has only one extruder then set this parameter to zero. If printer firmware doesn’t set offset by itself then you should set other extruders offsets relative to base (usually first) extruder. In this case you sholud set offsets for this base extruder offsets to zero.

Y offset (mm)

Y offset is the extruder Y offset relatively to the base point on a print head. If your printer has only one extruder then set this parameter to zero. If printer firmware doesn’t set offset by itself then you should set other extruders offsets relative to base (usually first) extruder. In this case you sholud set offsets for this base extruder offsets to zero.