A worm drive is a gear arrangement consisting of a worm (a screw-like shaft) and a worm wheel (a toothed gear). This configuration is used to transmit motion and power between two shafts that are typically at 90 degrees to each other. The worm meshes with the gear, and due to the sliding contact, the system allows for high torque transmission and significant speed reduction in a compact space. It is commonly non-reversible, meaning the gear cannot turn the worm, which adds a safety advantage in lifting or hoisting applications.