This article reviews the work done on neural networks in recent years. In recent years we have witnessed a continuous movement, from purely theoretical research to applied research, especially in the field of information processing, for problems for which there is no solution or which is not easily solved. Artificial neural networks are part of a group of dynamic systems, which, by processing experimental data, transfer the knowledge or law behind the data to the network structure. This is why these systems are called intelligent, because they learn general rules based on calculations based on numerical data or examples. These systems attempt to model the neuro-synaptic structure of the human brain. From the brain as an information processing system with a parallel and completely complex structure that makes up two percent of the body weight and consumes more than twenty percent of the body's total oxygen for reading, breathing, movement, thinking and exploring and the kidneys. Conscious actions and many unconscious behaviors are used. How the brain does these things has been around since they realized that the brain has a completely different structure for its computations than conventional computers?