A small, handheld wireless device capable of storing and/or transmitting pages, data messages, voice calls, faxes and e-mails. A typical PDA can function as a cellular phone, fax device, Web browser and personal organizer. Unlike portable computers, most PDAs began as pen-based devices that used a stylus rather than a keyboard for input. Many PDAs subsequently incorporate handwriting recognition features. Some PDAs can also react to voice input by using voice recognition technologies. Most PDAs are available in either a stylus or keyboard version. PDAs are also called palmtops, hand-help computers, Personal Information Managers (PIMs), and pocket computers.

	PalmOS
	Pocket PC