Use correlation for a quick and simple summary of the direction and strength of the relationship between two or more numeric variables. Use regression when you're looking to predict, optimize, or explain a number response between the variables (how x influences y).

When should correlation be used?

Correlation is used to describe the linear relationship between two continuous variables (e.g., height and weight). In general, correlation tends to be used when there is no identified response variable. It measures the strength (qualitatively) and direction of the linear relationship between two or more variables.

What is correlation best used for?

Correlation coefficients are used to measure the strength of the relationship between two variables. Pearson correlation is the one most commonly used in statistics. This measures the strength and direction of a linear relationship between two variables.