What is the difference between correlation and covariance

Question

In terms of data what is the difference between correlation and covariance?

Answer 1

Correlation and Co-variance both are used as a measure to check how two variables change with respect to each other.

Covariance: measure of change of how to variables change with respect to each other.

1. It is unit dependent.
2. Difference in scale can output different co-variance.
3. It varies from - infinity to infinity

Example: Height vs weight(kg) and Height vs weight(lbs) will have different covariance values

Correlation : unit measure of change between two variables change with respect to each other. ( Basically it’s normalized covariance value)

1. It is unit independent.
2. Difference in scale doesn’t affect the correlation value
3. It varies from -1 to 1.

Example: Height vs weight(kg) and Height vs weight(lbs) will have same correlation values

Answer 2

Covariance is a measure of the joint variability(change) of two random variables.

Correlation measures the mutual relationship or connection between two or more things.

Covariance is a measure of Correlation.