A Handheld device (also known as handheld computer or simply handheld) is a pocket-sized computing device, typically utilising a small visual display screen for user output and a miniaturised keyboard for user input. In the case of the personal digital assistant (PDA) the input and output are combined into a touch-screen interface. Along with mobile computing devices such as laptops and smartphones, PDAs are becoming increasingly popular amongst those who require the assistance and convenience of a conventional computer, in environments where carrying one would not be practicable.