Definition - What does Stylus mean?
A stylus is a pen-shaped handheld instrument used with touch screen input devices or graphics tablets in order to interact and input commands to the operating system or to draw on the screen. It is an input device typically used with handheld computers such as mobile phones and tablets, as well as for computers used in tandem with a graphics tablet and a painting program.
Techopedia explains Stylus
The term "stylus" originally meant "writing implement," and even in the context of computers a stylus is still used to write, among other things. When touch screen technology was in its infancy and the most prolific type of screen was the resistive touch screen which required pressure in order to register input, styli were nothing more than plastic-tipped implements used to press the screen to register touch input. But with capacity screens now the standard for mobile devices, the stylus has changed and now features special material on the tip that registers with a capacitive touch screen.
Though widely used for mobile devices, the stylus is more known as a drawing instrument used in conjunction with a digitizing tablet or graphics tablet and used by digital artists as input devices. This is because drawing or painting, even on a computer, is still easier by hand and near-impossible when using a mouse, track pad or trackball. These types of styli often have some electronic components in them that give them various functions such as additional buttons for customizable options like assigning specific tools and colors to each button. A professional drawing stylus can register various degrees of pressure that would reflect in the painting program as thinner or bolder strokes, or darker or lighter colors. These professional styli often pair up with a corresponding digitizing tablet and may not work properly when used with another model of digitizing tablet.