Standard deviation is considered to be the best measure of dispersion and is thereore, the most widely used measure of dispersion.
(i) It is based on all values and thus, provides information about the complete series. Because of this reason, a change in even one value affects the value of standard deviation.
(ii) It is independent of origin but not of scale.
(iii) It is useful in advance statistical calculations like comparison of variability in two data sets.
(iv) It can be used in testing of hypothesis.
(v) It is capable of further algebraic treatment.