Regression is a fundamental statistical method used in supervised learning to analyze the relationship between independent variables and a dependent variable. It aims to model the output as a function of the input features, allowing for predictions and insights into data trends. The most common form, linear regression, establishes a linear relationship, represented by an equation such as y = ax + b, where ‘y’ is the dependent variable, ‘x’ is the independent variable, and ‘a’ and ‘b’ are coefficients. Regression techniques are widely applied in various fields, including economics, biology, and engineering, to understand and predict outcomes based on historical data.