PDD stands for Personal Data Device and is a general term describing a vast variety of such devices almost every Union Citizen has. PDD's may be implanted as it is common on Pluribus Unum and work in conjunction with Data Head devices or be worn hidden in Jewelry, clothing items such as shoes, gloves etc. The most common ones are the bracelet type. Very popular especially within the military and professionals are hand held devices which are stored in belts or pockets when not in use.
Even though micro miniaturization makes it possible to integrate most of a PDD's functionality inside a button or a small implant, the general population and especially professionals who use PDD's on a daily basis in Clipboard mode or as read outs prefers handheld or wrist based PDD's.
PDD's with their own Translight GalNet Capability are available but usually very expensive. Standard models link into existing local networks.