number that's summation and we pass it through what's called a nonlinear activation function and that produces our final output Y now this is actually not entirely correct we also have what's called a bias term in this neuron which you can see here in green so the bias term the purpose of the bias term is really to allow you to shift your activation function to the left and to the right regardless of your inputs right so you can notice that the bias term doesn't is not affected by the X's it's just a bias associate to that input