What is a passive or capacitive pen/stylus?
A passive stylus (also called a capacitive stylus) is a pen that acts just like a finger when touching a device screen. There is no communication between a passive stylus and a device. A device cannot tell the difference between a finger and a passive stylus.
Advanced functionality can only be achieved with an active pen or a special passive stylus (such as the DirectStylus), which are only available for compatible devices.