But What Is a Neural Network?
Grant Sanderson
A visual introduction to neural networks that makes the math behind AI intuitive through stunning animations.
Why we picked this
The single best introduction to neural networks ever made. Sanderson turns abstract math into something you can see and feel.
Everyone talks about AI. Almost nobody understands what’s actually happening inside a neural network. Grant Sanderson’s 3Blue1Brown channel exists to fix exactly this kind of gap — he makes mathematical concepts visual, and in this video, he takes on one of the most important technical ideas of our era.
Starting with the simple challenge of recognizing handwritten digits, Sanderson builds up the structure of a neural network layer by layer. Neurons hold numbers. Connections have weights. Layers transform inputs into outputs. The animations don’t just illustrate the math — they are the explanation. You understand by watching.
This is Chapter 1 of his acclaimed deep learning series. It assumes no prior knowledge of AI or advanced math, but by the end you’ll have genuine intuition for how these systems work — not just buzzword-level familiarity.