Z pen is a wireless type pen. It has a clip that acts as a receiver to record digitally , what you write. It has capacity to uploads information in your computer.The data can be interpreted by handwriting software and it acts as a text entry interface. There are several types of technology in these digital pen such as Accelerometer , postiotional, Active , Camera , Trackball pen.
Accelerometer - These are to detect movement of the pen.
Active- These are activated with pen location, button presses, pressure etc.
Positional- During writing, these are detect to location .
Track ball - These are act as a sensor to detect motion of the trackball.
Camera - These use by Anonoto technology that act as the digital paper to detect the writing surface.