Correlation

Correlation is the degree or extent of the relationship between two variables or the determination of the effect of one variable upon another in a dependent situation. If the value of one variable increases when the value of the other increases, they are said to be positively correlated. If the value of one variable decreases when the value of the other decreases, they are said to be negatively correlated. The degree of linear association between two variables is quantified by the correlation coefficient.