Andrej Karpathy's Neural Networks: Zero to Hero — 1) Intro to Neural Networks and Backpropagation

Introduction

Andrej Karpathy uploaded several lecture videos on YouTube and the accompanying code on GitHub. I think they are excellent lectures, even better than many paid online courses. Here's the link: Neural Networks: Zero to Hero. So, I will summarize them and try to get meaningful insights from them. I'm going to cover all of them lecture by lecture (I hope...)

The first lecture is about backpropagation in neural networks.

The Spelled-out Intro to Neural Networks and Backpropagation

In the video, Karpathy said that backpropagation is what you need to train neural networks, and everything else is mainly for efficiency. That is why he explained and demonstrated backpropagation in the very first video.