DressingThe purpose of dressing is to restore the correct cutting action of the wheel. Dressing removes the clogs on the surface of the wheel and the blunt grains of the abrasive, exposing the new sharp abrasive grains of the wheel which can be cut and brought to shape efficiently.
TruingTruing refers to the shaping of the wheel to make it run concentric with the axis. When a new grinding wheel is mounted, it must be trued before use. The cutting surface of a new wheel may run out slightly due to the clearance between the bore and the machine spindle. Grinding wheels, which are in use, also can run out of true, due to uneven loading while grinding.
Dressing and truing are done at the same time using same tool.

Floating blade reamer is used to correct the misalignment between the reamer axis and the work axis.

Grinding wheel with diamond abrasive is suitable for grinding glass.