the.com/track switch

means A movable section of track that guides a train from one line onto another, determining its route.

from 'Switch' in this sense comes from railway engineering language of the 1800s, when the device itself was often called a 'switch' or 'points' (the British term, still used today). The word 'switch' itself traces back to a slender flexible rod or twig — the kind used for whipping or flicking — and picked up the sense of 'a device that flicks something from one state to another,' which is exactly what a track switch does to a train's path. The electrical switch borrowed the same word later, for the same reason: a small flick, a big change of direction.