Measurement is actually the process of estimating the values that is the physical quantities like; time, temperature, weight, length etc. each measurement value is represented in the form of some standard units.The estimated values by these measurements are actually compared against the standard quantities that are of same type.

In the beginning, the term mensuration was used instead of measurements. The metrology is a term used to refer to the study of measurements. These measurements or estimation of physical values can not be accurate. It always bears some chances of errors. These errors in measurements are normally distributed about the actual measurement. Thus, each measurement can be described as containing three components as; an estimated value, an error bound, and the probability of finding the actual measurement within the range of error bounds of that estimated measurement.

The process of measurement basically depends upon the specification of standard quantities or units. These units have almost been defined for each physical quantity. For instance the standard unit of length is meter. There is a standard system of base units form which we can derive many other units. These derive units are also used similarly for measurements.There are many systems of units in use like; imperial system, metric system and SI system of units.

In the beginning, the term mensuration was used instead of measurements. The metrology is a term used to refer to the study of measurements. These measurements or estimation of physical values can not be accurate. It always bears some chances of errors. These errors in measurements are normally distributed about the actual measurement. Thus, each measurement can be described as containing three components as; an estimated value, an error bound, and the probability of finding the actual measurement within the range of error bounds of that estimated measurement.

The process of measurement basically depends upon the specification of standard quantities or units. These units have almost been defined for each physical quantity. For instance the standard unit of length is meter. There is a standard system of base units form which we can derive many other units. These derive units are also used similarly for measurements.There are many systems of units in use like; imperial system, metric system and SI system of units.