AI is a advanced concept which is now having been achieved a lot .AI uses a neural network as basement to do anything the programer wants it to do. And also,you will see,the artificial neural network imitates a lot from a natural one. And one neron can do only 1 and 0,so it's necessary to have a complex neural network.this is the reason why the we have a neural network contains many layers which can be devided int three parts,the input layer，the hidden layer,and the output laye