variability

As a statistical term, this is pretty close to its everyday meaning: how much data items vary from each other – are they all quite close, or do they vary over a wide range of values? There are various measures of variability, from the absolute range (maximum–minimum) to the interquartile range, or the ubiquitous standard deviation. For a theoretical distribution you can think of this as how widely spread the graph is, or how variable you would expect data that conforms to the distribution to be.