(Personal Digital Assistant) A handheld computer for managing contacts, appointments and tasks. It typically includes a name and address database, calendar, to-do list and note taker, which are the functions in a personal information manager (see PIM). Wireless PDAs may also offer e-mail and Web browsing, and data are synchronized between the PDA and desktop computer via USB or wireless. If the PDA includes a phone, it falls into the smartphone category (see smartphone).

Newton Was the Pioneer
In 1993, Apple's MessagePad, more commonly known as the "Newton," was the pioneer in this field, and Apple CEO John Sculley actually coined the PDA term for a pen-based device. However, PalmPilots, introduced a couple years after, popularized the technology. When the BlackBerry offered synchronized e-mail in 1999, the PDA was on its way to becoming a mobile office.

Pen or Key Based
PDAs may use a pen or keys. With pen-based PDAs, users tap menus and enter text via an on-screen keyboard with a stylus that slides into a holder on the side of the unit. Lightweight, full-size, folding keyboards can be connected and used when a desk surface is available.

Key-based units have tiny physical keyboards and various cursor keys and scroll wheels. For example, the BlackBerry's "thumbwheel" opens a context-sensitive menu of options and is clicked to select one. See Newton, Palm, BlackBerry and thumb culture.