Kernel Function In this post, We'll know what exactly is kernel function. Kernel Function is used to transform n - dimensional input to m- dimensional input , where m is much higher than n then find the dot product in higher dimensional efficiently.It also helps sometimes to do calculation easily in infinite dimensional space without going to infinite dimensions. Mathematical definition : K(x, y) = <f(x), f(y)> . Here K is the kernel function, x, y are n dimensional inputs. f is a map from n-dimension to m-dimension space. < x,y> denotes the dot product. usually m is much larger than n. Intuition : Normally calculating <f(x), f(y)> requires us to calculate f(x), f(y) first, and then do the dot product. These two computation steps can be quite expensive as they involve manipulations in m dimensional space, where m can be a large number. But after all the trouble of going to the high dimensional space, the result of the dot product is really a scala