This document discusses and compares different methods for deep learning object detection, including region proposal-based methods like R-CNN, Fast R-CNN, Faster R-CNN, and Mask R-CNN as well as single shot methods like YOLO, YOLOv2, and SSD. Region proposal-based methods tend to have higher accuracy but are slower, while single shot methods are faster but less accurate. Newer methods like Faster R-CNN, R-FCN, YOLOv2, and SSD have improved speed and accuracy over earlier approaches.