Descriptive statistics are used to describe a data set, whether that be the full data set or a sample. There are two categories of descriptive statistics — measures of central tendency and measures of variability or spread. Measures of central tendency look at the center of a data set while measures of variability look at how the data is dispersed.
Measures of central tendency include mean, median, and mode, which measures the most common patterns within the data. Measures of variability include standard deviation, variance, range, quartiles, absolute deviation, the minimum and maximum variables, and the kurtosis and skewness. Measures of variability help in determining the shape of the distribution.