A Correlation Coefficient is a statistical concept expressed as the letter “r” that measures the strength and type of the relationship between two factors (‘X’ and ‘Y’).
A Correlation Coefficient is a number between -1 and +1. An ‘r’ of +1 means that there is a perfect, positive correlation between X and Y and the changes in Y can be attributable to X. Conversely, an ‘r’ of -1 means that there is a perfect negative correlation between X and Y and the changes in Y can be attributable to X.