Brandon Rohrer explains back propagation using plumbing.
What is back propagation, you ask? Well, it’s our old friend gradient descent’s new name when it is applied to neural networks.
If that explanation doesn’t work for you, then check out this video, where Siraj Raval explains back propagation in a way only he can: in song. Best of all, aside from the sick beats, is that the source code from the video is available on GitHub.