Correlation

The degree to which two variables[∂] change together (are associated).

Variables that change together in the same direction — as one increases, the other increases; or as one decreases, the other decreases (such as height and weight) — are said to be positively correlated.

Variables that change together in opposite directions — as one increases, the other decreases (such as the amount of sunlight and the amount of rain) — are said to be negatively correlated.