Artificial neural networks have become a significant part of artificial intelligence and are used in machine learning.  They are brain motivated systems ‘neural’ which replicate the way that humans learn.  Neural networks (also called ‘perceptrons’) consist of input and output layers in addition to a hidden layer which includes units that transform the input into something that the output layer can use.  Artificial neural networks are exceptional tools for locating patterns which are too complicated for a human programmer to extract the right information to teach the machine to recognise.  The technique backpropagation is an arrival to neural networks and allows adjustment to the hidden layers of neurons. Another important advance has been deep learning neural networks, in which different layers of a multilayer network extract various features until it can recognise what it is searching.