Measurement is crucial in everyday life as well as in all branches of science, business, and industry. Using a measuring device is necessary for measurement. Calibration is a group of methods used to create a connection between the values of quantities reported by measuring devices and systems under specific circumstances. Comparing the device to primary or secondary standards is part of the calibration procedure. Calibration is essentially the comparison of a higher standard that can be linked to a national or international standard or an accepted alternative under specific conditions. Examining the concept of calibrating with a focus on the requirements, benefits, and approach is the aim of this chapter. Traceability is a crucial factor in establishing the precise calibration of a standard or instrument by comparing it to higher standards one at a time until it reaches a recognized norm on a national or international scale.