Personal Digital Assistant. A handheld device that combines computing, telephone/fax, and networking features. A typical PDA can function as a cellular phone, fax sender, and personal organizer.
Unlike portable computers, most PDAs began as pen-based, using a stylus rather than a keyboard for input. This means that they can incorporate handwriting recognition features. Some PDAs can also react to voice input by using voice recognition technologies. PDAs are available in either stylus or keyboard versions. Pocket PCs and smartphones are equal to PDAs.