Correlation coefficient (r) is a number between −1 and +1 calculated so as to represent the linear dependence of two variables or sets of data.
The correlation coefficient shows the type of association between two variables. The value of the correlation coefficient is between -1 and +1.
A negative correlation coefficient that is closser to -1 indicates a strong negative association while a positive correlation coefficient that is closser to +1 indicates a strong positive association.
Also, a negative correlation coefficient that is closser to 0 indicates a weak negative association while a positive correlation coefficient that is closer to 0 indicates a weak positive association.
A correlation coefficient of zero indicates that there is no association between the two variables.