The thing that makes neural networks appear challenging, is the math that is involved, and how scary it can sometimes look. For example, let’s imagine a neural network, and take a journey through what’s going on during a simple forward pass of data, and the math behind it. For this, do not worry about understanding every- thing. The idea here is to give you a high level idea of what’s going on overall, and then the point of this book is to break down each of these elements into painfully simple explanations, which will cover both forward and backward passes involved in training neural networks.