Neural networks and the human brain
Neural networks are inspired by the human brain structure, the basic idea being that a group of objects called neurons are combined into a network. Each neuron receives one or more inputs and a single output based on internal computation. Neural networks are therefore a specialized kind of directed graph.
Many neural networks distinguish between three layers of nodes: input, hidden, and output. The input layer has neurons that accept the raw input; the hidden layers modify that input; and the output layer produces the final result. The process of moving data forward through the network is called feedforward.