Covariance and correlation are two different measures of how two variables change together. Covariance is the absolute value of the product of the deviation of each variable from its mean, while correlation is a unitless number that ranges between -1 and 1. In most cases, covariance and correlation will be similar, but there are some situations where they can give different results. It’s important to understand the difference between these two measures so you can choose the right one for your data.

## What is Covariance?

A covariance is a statistical tool that is used to measure the relationship between two variables. Covariance can be positive or negative, and it is a measure of how two variables change in relation to each other. For example, if two variables both increase when the other increases, they have positive covariance. If one variable increases while the other decreases, they have a negative covariance. Covariance is used in statistics to help predict future behavior based on past behavior. It can also be used to assess risk. A covariance is a useful tool for any situation where understanding the relationship between two variables is important.

## What is Correlation?

Correlation is a statistical measure that describes the strength of the relationship between two variables. Correlation can be positive, negative, or zero. A positive correlation means that as one variable increases, the other variable increases.

- A negative correlation means that as one variable increases, the other variable decreases. A zero correlation means that there is no relationship between the two variables.
- Correlation is often used to measure the relationship between stock prices and economic indicators. For example, a positive correlation between stock prices and economic growth might indicate that investors are confident in the economy and are willing to invest in stocks.
- A negative correlation between stock prices and economic growth might indicate that investors are worried about the economy and are selling off stocks.

Correlation can also be used to measure relationships between other variables, such as temperatures and precipitation levels. Correlation is not the same as causation, which is a measure of how one variable affects another. Correlation simply measures the strength of the relationship between two variables.

## Difference between Covariance and Correlation

Covariance and correlation are two statistical measures that are often used to determine the relationship between two variables. Covariance is a measure of the degree to which two variables vary together. Correlation, on the other hand, is a measure of the degree to which two variables are linearly related.

In other words, correlation measures the strength of the linear relationship between two variables. Covariance can be used to measure the relationship between two non-linear variables, but it is not as accurate as correlation. In general, correlation is a more reliable measure of the relationship between two variables.

## Conclusion

Covariance and correlation are two important measures of association used in statistics. It is important to understand the difference between them, as they can produce different results. In general, covariance is more sensitive to outliers than correlation, and it is usually preferred when measuring the linear relationship between two variables. However, if you are only interested in the magnitude of the relation between two variables, then correlation may be a better measure.