Frequency data occur when we classify statistical data in respect of either a variable or an attribute. A frequency distribution is a tabular representation of statistical data, usually in an ascending order relating to a measurable characteristic according to the individual value or a group of values of the characteristic under study.
Frequency distribution is a statistical table that distributes the total frequency to a number of classes.
In case, the characteristic under consideration is an attribute, then the tabulation is made by allocating numerical figures to the different classes the attribute belongs to. When tabulation is done in respect of a discrete random variable, it is known as Discrete or ungrouped frequency distribution and in case the characteristic under consideration is a continuous variable, the classification is termed as Grouped frequency distribution.