Neural networks are networks of nerve cells in the brains of humans and animals. The human brain has about 100 billion nerve cells. We, humans, owe our intelligence and our ability to learn various motor and intellectual capabilities to the brain’s complex relays and adaptivity. For many centuries biologists, psychologists, and doctors have tried to understand how the brain functions. Around 1900 came the revolutionary realization that these tiny physical building blocks of the brain, the nerve cells, and their connections, are responsible for awareness, associations, thoughts, consciousness, and the ability to learn.