Now an idea that will come up very frequently in statistics is the notion of variability. Variability. In everyday language, variability, it's how much something is, how much does it vary? How much does it change? And it's the same notion in statistics. In statistics, variability is the degree to which data points are different from each other, the degree to which they vary. And just as an example of that, to just make it a little bit more concrete, let's say you were to go to five people and you were to ask them, how many bricks did you eat yesterday?