The term variability, "the state or characteristic of being variable", describes how spread out or closely clustered a set of data is. This may be applied to many different subjects:

• Climate variability
• Genetic variability, a measure of the tendency of individual genotypes in a population to vary from one another
• Heart rate variability, a physiological phenomenon where the time interval between heart beats varies
• Human variability, the range of possible values for any measurable characteristic, physical or mental, of human beings
• Spatial variability, when a quantity that is measured at different spatial locations exhibits values that differ across the locations
• Statistical variability