In computing, a stylus is an instrument shaped like a pen, designed to be used with graphics tablets or devices that use touch screen input. It is used to write or draw on a screen, similar to how you would on a sheet of paper. Unlike a pen, styluses have a plastic or felt tip depending on its purpose and functionality. The picture shows the Palm Z22 stylus.
Which devices use a stylus?
Originally, the stylus was not commonly found or used with devices other than graphics tablets and PDAs. However, with the rising popularity of touch screens on mobile devices, many individuals like using a stylus instead of their finger. The reasoning varies, but it's usually for more accurate navigation and keeps oils from their fingers from getting on the device's screen.
If you've had to sign your signature for a credit card purchase, you've likely used a stylus to sign your name.
What is the difference between passive and active styluses?
A stylus can come in two forms: passive (also known as a capacitive stylus) or active (also known as an active stylus or active pen). A passive stylus is not different than using your finger as far as the device is concerned. An active stylus (such as the one used with the Microsoft Surface) has an electronic component that interfaces with the device's touch screen controller. They have a few distinct advantages: more accurate and finer lines, different levels of pressure sensitivity, and the ability to ignore input from your hand resting on the screen. The last feature is called palm rejection.
How is a stylus an input device?
Before the touch screens we know today, the stylus was used to input data into small palmtop devices. This form of input may be known as pen input. For example, the Palm Pilot used the stylus to write symbols known as graffiti to input letters into the device.
Today, a stylus is still considered an input device because it can point to and open or manipulate objects on a screen, like a computer mouse. However, it is not as common now with more sophisticated touch screens capable of reading the user's finger. Newer computers also use handwriting recognition software to help take your handwritten notes into easy to read and share text.
What is a digital pen?
A stylus is a small basic plastic or steel device that is only used to input data. A digital pen resembles a stylus but is bigger and has its own capabilities.
For example, a digital pen may have a digital eraser that allows the pen to be flipped over and used as an eraser when drawing. Digital pens are also pressure-sensitive, allowing you to draw or paint on the screen depending on how hard you're pressing down on the pen. Other features may be one or more buttons on the pen that performs a special function, such as changing the brush type or size. Because of these additional capabilities, they also require batteries.