Stationary robots stay in one place but are usually equipped with an articulated limb for sorting or palletization. Rail-guided robots use rails, wires or magnetic tape to guide themselves from place to place. These robots aren't highly autonomous and are typically used as transportation systems. Laser-guided robots use lasers, labels and geo-guidance to position themselves within the warehouse. These robots are highly autonomous but may still have difficulty recognizing and avoiding human workers. LiDAR-equipped robots can use high-resolution scanners to navigate the warehouse with high autonomy, avoiding obstacles, following human workers and identifying new tasks as they come up.