Neural networks are one of the most interesting machine learning models. Neural networks are inspired by the structures of the brain. Neural networks are algorithms that mimic the functioning of the brain. They are unsupervised algorithms, which means that we do not always know what the outputs should be.
The input layer consumes the data, and the output layer represents the result. The middle layer represents the part of the algorithm that indicates how the input layer gets to the output layer.
The simplest type of neural network is known as a Feedforward Neural Network. It feeds information in one direction only, from the front to the back. This type of network is also known as a perceptron. The following figure illustrates a perceptron:
Neural networks can also feed information back down through the layers...