Active pen

An active pen (also referred to as active stylus) is an input device that includes electronic components and allows users to write directly onto the display of a computing device such as a smartphone, tablet computer or ultrabook. The active pen marketplace has long been dominated by N-trig and Wacom, but newer firms Atmel and Synaptics also offer active pen designs.

An active pen is generally larger and has more features than a stylus. Digital pens typically contain internal electronics and have features such as touch sensitivity, input buttons, memory, writing data transmission capabilities, and electronic erasers.

The main difference between an active pen and the input device known as a passive stylus or passive pen is that although the latter can also be used to write directly onto the screen, it does not include electronics and thus lacks all of the features that are unique for an active pen: touch sensitivity, input buttons, etc. Active pen devices support most modern operating systems, including Google's Android and Microsoft Windows.