This document discusses OpenCV and its modules. OpenCV is an open source library for computer vision and machine learning. It contains over 2500 algorithms for tasks like object detection, face recognition, video analysis, image processing and more. Some key modules include core, imgproc, dnn, ml, video, highgui, features2d, flann, stitching, objdetect. These modules provide functionality for tasks like image processing, neural networks, regression, clustering, video analysis, window display, feature detection and more.