Cluster analysis is a form of exploratory data analysis in which observations are divided into groups that share common characteristics. Those groups are compared and contrasted with other groups to derive information about the observations.
Correlation analysis, also known as bivariate analysis, is primarily concerned with finding out whether a relationship exists between variables and then determining the magnitude and action of that relationship.
Predictive modeling is a statistical technique and process used to forecast future outcomes. It is most closely associated with predictive analytics, which focuses on using machine learning to predict what might happen next.