what is lidar in robotics?

Lidar almost never works alone: it is the raw material of SLAM, the algorithm a robot uses to build its map and locate itself within it. Warehouse AMRs have navigated this way for a decade, and the technology has dropped in price all the way down to mid-range robot vacuums, the same journey the Roomba's navigation made from blind bouncing to a full map of your home.

Its rival is camera vision, cheaper and semantically richer (a camera can tell a puddle from a shadow; a lidar cannot), and the trend in serious robots is to combine both. When a maker brags about obstacle avoidance, the useful technical question is which sensors and how many planes: a 2D lidar sees one slice of the world at sensor height; a 3D one sees the whole scene.