Regression analysis is a statistical process for estimating the relationships between two or more variables. The relationship is modeled as \(y \sim x\) or \(y = f(x)\). Both model descriptions indicate that the variable \(y\) is a function of \(x\). Therefore the variable \(y\) is denoted as **response variable** or **dependent variable**, whereas the variable \(x\) is denoted as **predictor variable** or **independent variable**.