Correlation is a statistical measure that indicates the degree to which two or more variables are related or move together. It quantifies the strength and direction of the relationship between two variables. In other words, it shows whether the variables are positively or negatively related, or not related at all.
The correlation coefficient is a common measure used to express the degree of correlation between two variables. It ranges from -1 to 1, where -1 indicates a perfect negative correlation, 0 indicates no correlation, and 1 indicates a perfect positive correlation.
A positive correlation indicates that as one variable increases, the other variable also tends to increase. For example, there is a positive correlation between the amount of exercise a person gets and their level of physical fitness. The more exercise a person gets, the more physically fit they tend to be.
On the other hand, a negative correlation indicates that as one variable increases, the other variable tends to decrease. For example, there is a negative correlation between the amount of sleep a person gets and their stress level. The less sleep a person gets, the more stressed they tend to be.
It is important to note that correlation does not necessarily imply causation. Just because two variables are correlated does not mean that one variable causes the other. In order to establish causation, a deeper analysis is needed, such as through experimental studies or regression analysis.