Mask R-CNN is a neural network model that performs both object detection and segmentation. It uses a Feature Pyramid Network and ROI Align to extract features from each region of interest and predict a segmentation mask in addition to class and bounding box. Mask R-CNN has been implemented in frameworks such as TensorFlow, Chainer, and MXNet and can be used for tasks like instance segmentation, keypoint detection, and depth segmentation from Kinect data.