A correlogram is a visual representation of a correlation matrix. It uses color and/or size to indicate the strength and direction of correlation between multiple variables. This chart type makes it easier to identify which variables are closely related and which are not.
For example, in a dataset of health indicators, a correlogram might show that body mass index and blood pressure are strongly positively correlated, while smoking rate and exercise frequency are negatively correlated.
Correlograms are useful in feature selection, multicollinearity detection, or general data exploration.