Regression analysis involves finding the line of best fit through a series of points. The calculation to find the line of best fit uses the least squares method and the outcome is a regression equation.
Regression analysis should always be carried out in conjunction with correlation analysis to find the goodness of fit.
Types of regression analysis include:
Note that if there are several inputs and/or outputs multivariate analysis is used. Strictly speaking multiple linear regression is a form of multivariate analysis although not usually referred to as such.