Polynomial Regression means to fit a curve from a given set of points, which has the least possible error.
When a given set of points does not satisfy a linear equation, you can try a suitable polynomial as a regression curve to fit in given data.
Least square technique can be used to fit data to a polynomial
Consider a polynomial of degree ( m-1 )
Y = a1 + a2x + a3x2 + … amxm-1
Polynomial Regression Formula