Support Vector Machines and Kernels for Computational Biology
The region between the two thin lines defines the margin area with −1≤〈w,x〉+b≤1. The data points highlighted with black centers are the support vectors: the examples that are closest to the decision boundary. They determine the margin by which the two classes are separated. Here, there are three support vectors on the edge of the margin area (f(x) = −1 or f(x) = +1).