The function of a meter stick is to measure the length of an object or distance using the metric system. The length or distance shouldn't be extremely small or large in order to obtain an accurate and efficient result.
The metric system is the main measurement system in the world. Almost all major countries have adopted it as the official measuring system. The meter is one of the standard units for length. A meter stick is exactly one meter long, but it also has markings to divide it into centimeters and sometimes millimeters. The equivalent in the imperial measurement system is the yard, which is slightly longer than a meter.