There are three types:

- Positive correlation (r > 0)

- Negative correlation (r < 0)

- No correlation (r =0)

There are three main types of correlation:

1. Positive Correlation: This occurs when both variables move in the same direction. As one variable increases, the other also increases, and as one decreases, the other decreases. For example, a positive correlation might be observed between hours studied and test scores.
2. Negative Correlation: This occurs when the variables move in opposite directions. As one variable increases, the other decreases, and vice versa. An example might be an increase in temperature leading to a decrease in heating costs.
3. Zero (or No) Correlation: This means there is no linear relationship between the variables. Changes in one variable do not predict any consistent changes in the other. For example, shoe size and intelligence generally show no correlation.