What does a correlation coefficient of 0 indicate?

A correlation coefficient of 0 indicates that there is no linear relationship between the two variables being analyzed. The correlation coefficient, which ranges from -1 to +1, measures the strength and direction of a linear relationship. A value of 0 suggests that changes in one variable do not predict changes in the other variable. This means that there may be no correlation or relationship at all; the variables can be completely independent or related in a non-linear way.

In contrast, a correlation coefficient closer to +1 indicates a strong positive relationship, where as one variable increases, the other also tends to increase. Similarly, a correlation coefficient closer to -1 indicates a strong negative relationship, where one variable increases while the other decreases. Thus, a coefficient of 0 is indeed indicative of no linear correlation between the variables.