A 3D scanner is a device that captures the shape and appearance of a physical object by collecting data from its surface. It uses various technologies, such as laser or structured light, to create a digital 3D model. This model can be used in various fields, including engineering, art, and medicine. The scanned data can be processed and analyzed using specialized software, allowing for precise measurements and modifications. 3D scanning is commonly used in industries like manufacturing for quality control, in healthcare for creating prosthetics, and in entertainment for character modeling in video games and movies.