The following image represents a simple two-layer neural network:
Simple two-layer neural net
The first layer is the input layer and the last layer is the output layer. The middle layer is the hidden layer. If there is more than one hidden layer, then such a network is a deep neural network.
The input and output of each neuron in the hidden layer is connected to each neuron in the next layer. There can be any number of neurons in each layer depending on the problem. Let us consider an example. The simple example which you may already know is the popular hand written digit recognition that detects a number, ...
