This document provides an overview of deep learning techniques and their applications. It discusses various deep learning algorithms like convolutional neural networks (CNNs), recurrent neural networks (RNNs), autoencoders, and sparse coding networks. It also reviews literature applying deep learning methods to areas such as computer vision, natural language processing, recommender systems, and more. Tables are provided comparing different deep learning algorithms and summarizing related works applying these techniques. The document discusses techniques for addressing overfitting in deep neural networks. In summary, this document surveys the state-of-the-art in deep learning methods and their applications across multiple domains.