Lidar and photogrammetry are both methods used for capturing three-dimensional (3D) data of the environment, but they differ in the way they acquire this data. Lidar (Light Detection and Ranging) is a remote sensing technology that uses lasers to emit light pulses and measure the time it takes for those pulses to reflect back from objects in the environment. By calculating the amount of time it takes for the light to travel and return, lidar can create a precise 3D map of the environment. Photogrammetry, on the other hand, uses photographs to create 3D models. It works by taking multiple overlapping photos of an object or area from different angles, and then using specialized software to analyze the images and create a 3D model. In summary, the main difference between lidar and photogrammetry is the technology used to capture the 3D data. Lidar uses lasers to measure distances and create a 3D map, while photogrammetry uses photographs to create a 3D model. Both technologies have their advantages and disadvantages, and the choice of which to use depends on the specific requirements of the project.