Points (refered as switches in early US narrations) are mechanical installations on track used to guide engines from one track to another. They are controlled by signalmen so that they can guide engines to their destinations or in a siding should something go wrong with either an engine or its train. Some points, primarily ones used in branch lines or shunting yards, can also be controlled with a lever next to it.
Sometimes, when the weather gets extremely snowy and cold, the snow freezes the points and sometimes leads to serious accidents. When Henry was pulling the Flying Kipper, a set of points were frozen due to the weather, and led him crashing into a goods train. The same thing would later happen to Oliver when he was delivering goods to the Mountain Village, but wound up crashing into a snowman.
There are also special kind of points that end known as "Trap-Points" that are used to divert runaway trucks off the rails should they break away. Clarabel once came off the rails from the trap points when Thomas slipped backwards down the hill from Daisy's oil. In an annual story, Henry once thought that trap-points were silly, but his opinion changed when a firelighter carelessly left his regulator opened and caused him to move out onto the main line. Luckily, he was saved from a near collision with Gordon by the trap-points.