Light Detection and Ranging or more commonly referred to by its acronym as LiDAR are laser scanning survey where laser pulse are emitted, reflected off surfaces then collected which will generate 3D visual representation of the area that has been scanned. Not only a precise dimensional representation would be displayed, accurate positioning coordinates would also be collected via a Global Navigation Satellite System (GNSS) receiver which will record the emitted laser pulse and the coordinate of the surface it has reflected off from.
LiDAR is a remote sensing method that uses laser to measure the elevation like the ground, forest, and buildings.
It uses the ultraviolet, visible, or near-infrared source to sense objects. Light energy emitted by LiDAR system is known as Pulse and light reflected from the ground/object is known as Return.