When there is a correlation between two variables, it indicates that when the value of one variable changes, the other variable also changes in one direction. There is a difference between correlation and regression. Determining this relation is quite helpful since you can use the value of one variable to predict the value of another variable successfully. For instance, height and weight also have an appositive correlation because as the height of a person increases, the weight normally increases as well. Consequently, if you see an individual who is unusually tall, it can be said that their weight is also higher than average.