This chapter deals with a brief introduction to deep learning. We deal with the perceptron classifier and its training. We then deal with feedforward networks and the multilayer perceptron (MLP). Training MLP using the well-known backpropagation algorithm is examined. An introduction to convolutional neural networks (CNNs), recurrent neural networks (RNNs), Long Short-TermMemory (LSTM), and autoencoders is provided.