Mean- average of a set of numbers, or distribution
Median-the numeric value separating the higher half of a sample, a population, or a probability distribution, from the lower half. (better if there are one or two really low or high numbers that might throw an average way off).
Variance-A measure of the dispersion of a set of data points around their mean value. Variance is a mathematical expectation of the average squared deviations from the mean. Variance measures the variability (volatility) from an average. Volatility is a measure of risk, so this statistic can help determine the risk an investor might take on when purchasing a specific security.