Regression analysis is a predictive modeling technique used to investigate relationships between variables. There are several types including linear, logistic, and polynomial regression. Linear regression establishes relationships between dependent and independent variables using a best fit line. Logistic regression is used when dependent variables are binary. Polynomial regression allows independent variables to have powers higher than one. Regression analysis can be useful for human resources forecasting, determining staffing needs based on factors like projected sales or call volumes. It indicates significant relationships between dependent targets and independent predictors.