A correlation chart or correlation matrix represents the table that indicates the correlation coefficients between different sets of variables
Basically, a correlation matrix is displayed as a "square", with the same set of variables indicated in the rows and columns.
Every cell shows the correlation between the two sets of variables. A correlation matrix can be used, to sum up the data, as the input into a more sophisticated analysis, and as a precise definition for advanced analyses.
When creating a correlation matrix, the following key decisions need to be made: choice of correlation statistic, coding of the variables, treatment of missing information, and presentation.