Hello,
A linear function is a polynomial function of degree 1
(1,2,3,4,5,6,....)
A quadratic function is a polynomial function of degree 2
(1,4,9,16,25,49,64,81,...)
A exponential function is not a polynomial function (we may imagine a infinity degree)
(1,2,4,8,16,32,64,128,256,512,1024,...)