
Correlation is a statistical measure that shows the relationship between two variables. In simple terms, it tells you whether — and how strongly — two things are connected.
For example, if ice cream sales increase whenever the temperature goes up, we say there is a positive correlation between temperature and ice cream sales.
Correlation helps answer questions like:
Do two things increase together? (positive correlation)
Does one go up when the other goes down? (negative correlation)
Or are they unrelated? (no correlation)
The strength of the relationship is usually measured using a value called the “correlation coefficient,” which ranges between -1 and +1:
+1 → Perfect positive correlation
–1 → Perfect negative correlation
0 → No correlation
The closer the value is to +1 or –1, the stronger the relationship.
📌 Important: Correlation does not mean causation. Just because two things are related doesn’t mean one causes the other.