A neural network is a multi-layered model inspired by the human brain. Like the neurons in our brain, the circles above represent a node. The blue circles represent the input layer, the black circles represent the hidden layers, and the green circles represent the output layer. Each node in the hidden layers represents a function that the inputs go through, ultimately leading to an output in the green circles. The formal term for these functions is called the sigmoid activation function.

If you want a step by step example of creating a neural network, check out Victor Zhou’s article here.

If you’re a visual/audio learner, 3Blue1Brown has an amazing series on neural networks and deep learning on YouTube here.