The Normal distribution is used to analyze data when there is an equally likely chance of being above or below the mean for continuous data.
Data distributions is a function that specifies all possible values for a variable and also quantifies the relative frequency.
Central tendency is the idea that when using normal data, all three of the main measures (mean, mode, median) tend to be roughly the same.
Standard deviation is the measure of variation in a process. Describing variation by standard deviations lets us easily compare processes.
Dispersion is the degree of variation in the data. In other words, the extent of the spread of values from the mean.