Personal Digital Assistants (PDAs) are handheld devices that were originally designed as personal organizers, but became much more versatile over the years. A basic PDA usually includes a clock, date book, address book, task list, memo pad and a simple calculator. One major advantage of using PDAs is their ability to synchronize data with desktop, notebook and desknote computers.

The term personal digital assistant was coined on 7 January 1992 by John Sculley at the Consumer Electronics Show in Las Vegas, Nevada, referring to the Apple Newton.

The currently major PDA operating systems are: Linux, PalmSource's Palm OS, Pocket PC from Microsoft, and Symbian OS (formerly EPOC)

Some examples of PDAs:

• Apple Newton
• Casio Cassiopeia
• Franklin eBookMan
• Handspring Visor
• hp iPAQ Pocket PC (Originally Compaq iPAQ until HP merger in 2002)
• Nokia Series60
• Palm Pilot, Tungsten and Zire
• Sharp Wizard and Zaurus
• Sony CLIE
• Xircom REX 5000 and REX 6000
• Dell's Axim