A glider chair is a type of rocking chair that moves back and forth on a fixed track. The entire frame consists of a seat attached to the base by means of a double-rocker four-bar linkage, which causes the chair to simulate a rocking-chair motion as it swings back and forth. Gliders are used as alternatives to porch swings, and are also popular as nursery furniture for assisting parents in feeding newborn babies. They offer a smooth and gentle gliding motion that is less aggressive than traditional rockers. Gliders are more comfortable than traditional rockers, with wider seating and supportive armrests for bottle or breastfeeding, soft upholstery, and often have a recline option. They are marginally safer than rocking chairs for pets and toddlers, as pinch points are moved away from the floor.