 Artificial neural networks, the way they work, it was really inspired by how the human brain works. You have a bunch of interconnected, you can call them neurons, that work together to remember and process information. It's generally made up of multiple layers, at least modern ones, but the concept itself is not really that new. It was first proposed in the late 19th century, and the first computer-based neural network was done in the 50s. As time went on, it would be popular in research, and then people would realize, at least in the 50s, that they didn't have the compute power to do it, so it would die off for a while. Then people started talking about it more in the 70s, and then it kind of died off for the same reason. The use of neural networks really didn't start taking off until we had the growth of, in particular, GPUs.