3D reconstruction is a research area in computer vision and computer graphics that involves the process of capturing the three-dimensional shape of an object or scene from a set of 2D images or videos. This process typically involves techniques such as image processing, feature extraction, camera calibration, and triangulation to accurately reconstruct the 3D geometry of the object or scene. 3D reconstruction has applications in fields such as augmented reality, virtual reality, robotics, archaeology, and medical imaging.