LiDAR (Light Detection and Ranging) uses lasers to bounce light off of an object to generate a point cloud, much like radar bounces radio waves off an object to calculate its position in space. Invented in 1961 soon after the invention of the laser, LiDAR was first used by Apollo 15 to map the surface of the moon. It works by emitting a laser signal and calculating the time it takes for the signal to return after hitting a surface. Each measurement produces a data point, which, when collected in large quantities, forms a "point cloud." This point cloud can then be used to construct a detailed surface map.
LiDAR is often used on a large scale for archaeological surveys because it can detect features like building foundations through dense vegetation, but this method can be used on smaller objects as well. Most cell phones have a built-in laser to help the cameras focus in portrait mode, which the cell phone app Polycam repurposes to create LiDar scans of objects.
Often, LiDAR scanners designed for digitizing objects will be coupled with color cameras to record surface coloration, or 'textures'. The scanning software will then match the photos to the accompanying surface data points to overlay an image of the object onto the three dimensional surface. LiDAR scanners can have difficulty constructing a model of an object that is transparent, metallic, or reflective because these surfaces can affect the way that the laser bounces off of the object, throwing off the precise calculations needed to create an accurate point cloud.