A hand-held mobile device used for data storage and recording. Also known as a Personal Information Manager, PIM. It can be equipped with applications such as calendars, notepads, address books and even e-mail and Internet access capabilities.

A digital personal organiser, ranging from a simple "databank" to palmtop and hand-held computers. Popular products include the Palm and Psion series.

A small, hand-held computer that is used for a variety of simple tasks including organizers, word processing, etc. The common ones include the Palm Pilot and Apple's Newton. Most PDAs are less powerful than laptop computers but their small scale is a strong draw for many users.