Curve fitting is the process of constructing a curve, or mathematical function, that has the best fit to a series of data points, possibly subject to constraints.
Curve fitting is closely related to Regression analysis. In fact it is the techniques of Regression Analysis that we use to find the ‘best’ fit curve for the given data points.
In statistics, regression analysis is a statistical process for estimating the relationships among variables. It includes many techniques for modelling and analysing several variables, when the focus is on the relationship between a dependent variable and one or more independent variables (or ‘predictors’).
This kind of analysis of data is also called regression analysis, since one of the early applications of least
squares was to genetics, to study the well-known phenomenon that children of unusually tall or unusually short
parents tend to be more normal in height than their parents. In more technical language, the children’s height
tends to \regress toward the mean.”