PDA stands for personal digital assistant, a term for a new breed of handheld computers. PDAs are supposed to combine the power and flexibility of a real computer with the convenience of those little electronic organizers- the kind made by Sharp and Casio-that let you keep track of your names and addresses and to-do items.
A PDA can run much more complex software than an electronic organizer, and you're not stuck with the built in software-you can buy separate programs to customize the PDA to your specific tasks. With many PDAs you can use a stylus to write on the little screen. The PDA most people are talking about is the Newton, made by Apple, but many other companies are planning their own versions.