Millimeter (mm): The millimeter is equal to one one-thousandth of a meter (0.001 meters). It is frequently used for very precise measurements, such as the thickness of paper or the diameter of small objects.
Centimeter (cm): The centimeter is equal to one one-hundredth of a meter (0.01 meters). It is commonly used for measuring shorter lengths, such as the height of a person or the dimensions of objects.