An input tool that resembles and functions like a pen is called a stylus. It transmits a digital signal to a tablet that is suitable, which reads the pressure as sketching on the screen rather than using pen.

A standard stylus is a slender plastic shaft with a pen-like end curve. This kind of pen was included with early PDAs like the Apple Newton and the Palm Pilot. A silicone pen is also commonly used with digital signing devices for credit card transactions. Digital images are drawn on screens using only the plastic tip's pressure.

Advanced touchscreens on today's cellphones and laptops are made to be operated by human contact. They disregard touch from other sources, like a pen, to avoid accidental entry. As a result, contemporary touchscreen devices like the Apple iPad Pro and the Samsung Galaxy Note have special styluses with integrated receivers and sensors. For instance, the Apple Pencil uses Bluetooth to link up to the iPad. The iPad Pro precisely records the action of sketching on the screen by combining data from the pen and display.

Any pen with sensing or a digital connection to a gadget runs on batteries. As a result, a contemporary pen might require charging in order to function properly.