The document discusses handwritten digit recognition using neural networks. It compares three neural network approaches - deep neural network (DNN), deep belief network (DBN), and convolutional neural network (CNN) on a standard dataset. The results show that DNN achieved the highest accuracy rate of 98.08% while having similar processing time to the other algorithms. Previous work applying machine learning methods like SVM, KNN and CNN to handwritten digit classification are also reviewed, with CNN models achieving over 98% accuracy.