The difference between the measured value and the actual value."

If two persons use the same instrument for measurement for finding the same measurement, it is not essential that they may get the same results. There may arises a difference between their measurements. This difference is referred to as an "ERROR".Errors can be divided into three categories:(1) Personal Error(2) Systematic Error(3) Random ErrorPersonal Erro

-An error comes into play because of faulty procedure adopted by by the observer is called "PERSONAL ERROR".Personal error comes into existence due to making an error in reading a scale. It is due to faulty procedure adopted by the person making measurement.

-The type of error arises due to defect in the measuring device is known as "SYSTEMATIC ERROR".Generally it is called "ZERO ERROR". it may be positive or negative error. Systematic error can be removed by correcting measurement device.

-The error produced due to sudden change in experimental conditions is called "RANDOM ERROR".For example:During sudden change in temperature, change in humidity, fluctuation in potential difference(voltage).It is an accidental error and is beyond the control of the person making measurement.