Palm-size devices are, not surprisingly, designed to fit in the palm of your hand. They're enabled for editing and note taking, but primarily are used to reference schedules, organize to-do lists, and store and retrieve contact information. Portable keyboards with docking cradles are also available and sold separately. While most palm-size devices do not have internal modems , you can synchronize data with PCs and other PDAs using infrared ports or cradles.
External modems are also available for palm-size devices.
Stylus used to enter data. Handheld PCs are larger than palm-size devices. They are more expensive, but in return deliver increased functionality. Think of them as a compromise between the notebook computer and the palm-size device. Most handheld PCs have color screens, internal microphones, and speakers, plus CompactFlash and PC Card slots, infrared ports, and built-in modems.