Resolution
Barcode Resolution is the width of the narrowest bar of a 1D barcode or the smallest square of a 2D barcode. It is often quantified in the unit of Mil (one-thousandth of an inch, or 0.0254 millimeters). The resolution of an ordinary commodity EAN/UPC barcode is 13 Mil and a high-density barcode can be 4 Mil or 3 Mil.
Scanner Resolution is the width of the narrowest bar of a 1D barcode or the smallest square of a 2D barcode that a barcode scanner is able to read. It is often quantified in the unit of Mil (one-thousandth of an inch, or 0.0254 millimeters). Scanner resolution is directly proportional to the number of pixels of the sensor built into the scanner.