Abstract: Deep learning, viewed as a part of machine learning is capable of learning the essence of data from a small data set by learning a nonlinear network structure. Deep learning algorithms have shown wide use in speech recognition, image processing, video processing and has wide application in various areas which uses any of these techniques. Still many application areas are emerging and are untouched by deep learning architectures. This study gives an overview of various application areas where deep learning algorithms or variants are applied and proved beneficial. As well it gives a summary of the top five popular deep learning tools available for research and implementation of deep learning algorithms.