The series dealing with the discrete variable is called Discrete Series. The discrete variable refers to that characteristic which cannot be expressed in fractions or it is a frictionless variable. There will be either one employee or two. There cannot be 1.5 employee. The number of times each quantity or amount occurs, are shown in front of each quantity or amount which are known as frequencies. By frequency, we mean the number of times a particular observed value occurs or repetition of some items in the universe is known as frequencies.