A Personal Digital Assistant (PDA) is a small, lightweight minicomputer that can keep track of your appointments, phone numbers and addresses, grocery list plus all the things you need to do. PDA's can also keep you entertained with games, music, video, and even let you make phone calls. There are basically two different types of PDA's: the organizer with some PC features (Palm) and the handheld PC with organizer features (Pocket PC).
How you plan to use a PDA can best determine which operating system is best suited for you. Palm OS-based PDA's because of the simplicity of the operating system cannot multitask, It opens only one application at a time. Unless you use a third-party synchronization utility, the Palm OS will synchronize appointments and contacts only with its PC personal information manager, the Palm Desktop. Most places now sell Palm OS bundled with an Outlook filter to sync with that desktop PIM.
Pocket PC is basically a shrunken version of the desktop Windows OS unlike Palm, it can run numerous applications at once.The Pocket PC OS is complex compared with the Palm OS, but it offers Pocket PC versions of Microsoft Office applications like Outlook, Word, Excel, and PowerPoint that lets you use these programs as you would on your desktop.