Overlay keyboards are often used as a quick and easy way to input items with just two buttons.
Overlay keyboards generally consist of a flat grid of unmarked buttons.
nor do they require a great deal of fine motor control, making them ideal for people who have difficulty using a conventional keyboard.
Overlay keyboards are easy to clean, and resistant to spills or dust.
Overlay keyboards are probably most often found in fast food restaurants, where they reduce the amount of time required to enter items.