In computing, a stylus (or stylus pen) is a small pen-shaped instrument that is used to input commands to a computer screen, mobile device or graphics tablet. With touchscreen devices, a user places a stylus on the surface of the screen to draw or make selections by tapping the stylus on the screen. In this manner, the stylus can be used instead of a mouse or trackpad as a pointing device, a technique commonly called pen computing. Pen-like input devices which are larger than a stylus, and offer increased functionality such as programmable buttons, pressure sensitivity and electronic erasers, are often known as digital pens. The stylus is the primary input device for personal digital assistants. It is used on the Nintendo DS and 3DS handheld game consoles, and the Wii U’s Wii U GamePad. Some smartphones, such as Windows Mobile phones, require a stylus for accurate input. However, devices featuring multi-touch finger-input are becoming more popular than stylus-driven devices in the smartphone market; capacitive stylus, different from standard stylus, can be used for these finger-touch devices (iPhone, etc.). Also the stylus is used in the famous Galaxy Note series manufactured by Samsung Electronics. Graphics tablets use a stylus containing circuitry (powered by battery or operating passively by change of inductance), to allow multi-function buttons on the barrel of the pen or stylus to transmit user actions to the tablet. Some (probably most) tablets detect varying degrees of pressure sensitivity, e.g. for use in a drawing program to vary line thickness or color density. The first use of a stylus in a computing device was the Styalator, demonstrated by Tom Dimond in 1957.