Personal Access and Display Device
The P.A.D.D. is commonly referred to simply as a pad or a data pad. It is a common device used for centuries both on Federation and non-Federation worlds. The basic design and function dates back to pre-warp civilization on nearly every world. Its essential function is to provide a way to access and display information dynamically. Replacing more archaic methods of doing so such as a pen and paper combination (also called hard-copy on Earth) and books. Dynamic technical information, personal letters, literature, images, videos, and much more can be displayed on such a device.
Unlike a full computer terminal a PADD has limited internal memory but does contain wireless communication technology, using RF, subspace, or even infrared and laser communication systems. Connected to a data network the PADD is able to download and display nearly anything that is required in a compact form.
Most of these devices are designed to be handheld and between as small as 5" but as large as 12" depending on the model and purpose. The most common is a smaller 6" model designed to be easily fit in the hand and carried.
In the late 21st and early 22nd century Earth data pads began to largely supplant books and other non-digital medium, though books were never fully displaced even in the 24th century they did become more and more collectors and enthusiast items much the same way vinyl records did in the 20th century Earth after the advent of digital music storage and playback.