How does the Vernier Caliper works?

The vernier caliper consists of a main scale engraved on a fixed ruler and an auxiliary vernier scale engraved on a movable jaw. The movable auxiliary scale is free to slide along the length of the fixed ruler. This vernier's main scale is calibrated in centimeters with the smallest division in millimeters. The auxiliary scale has 10 divisions that cover the same distance as 9 divisions on the main scale. Therefore, the length of the auxiliary scale is 9.0 mm.