The uncertainty reflects the possible range of values in which the result of a measurement can exist. However, uncertainty varies from error, which is the difference between the measured result and the true value. For its representation, the uncertainty in a value is placed on the right of the result's magnitude, expressed in significant figures. The significant figure is the number of digits required to express the outcome without a loss of precision. The number of significant figures includes all digits of certainty and the digits of uncertainty on its right side. Uncertainty can be expressed in absolute and relative scales. Absolute uncertainty is the possible margin of variation for the result in both directions. On the contrary, relative uncertainty is the ratio of absolute uncertainty to the magnitude of the result.