A PDA is a personal digital assistant designed to be small enough in size to be considered as a hand-held device. Originally, they performed the simple tasks of an electronic personal organizer. Basic applications included a scheduler, contact list, task list, note blotter, clock and calculator.http://www.rxpgonline.com/article1731.html More modern incarnations of the PDA have made it a more complex and versatile device. Most now include color screens, enhanced audio and video applications, increased processor speeds and storage memory size. These innovations to the PDA have permitted them to become single unit, "hybrid", communication devices. In the modern day, a PDA is likely to function not only as a personal organizer; but also as a cellular telephone; an internet access device via a Wi-Fi connection and integrated web browser; and a portable entertainment center with sufficient integrated digital storage capacity to store large quantities of audio and video files, all playable through integrated media players.http://www.rxpgonline.com/article1731.html

Data Input

Earlier PDA's used the combination of a touchscreen and a stylus as the method to allow users to input data. Later models have incorporated more intuitive and sensitive touch screen technology that permits virtual QWERTY keyboards for data entry. Other models use miniaturized, physical QWERTY keyboards.http://www.statemaster.com/encyclopedia/Personal-Digital-Assistant

Synchronization

A key function for a PDA is its ability to synchronize data with a personal computer, server, network or other devices. This is accomplished with preloaded synchronization software, such as HotSync Manager, for Palm devices, or Microsoft ActiveSync, for Windows Mobile devices.http://www.statemaster.com/encyclopedia/Personal-Digital-Assistant

External Memory

Many PDA devices have Secure Digital (SD) or a Compact Flash slots to accommodate external memory cards.http://www.statemaster.com/encyclopedia/SDIO

Some models permit the user to use the SD slot to interface with {{SDIO]] compatible devices, such as external cameras, Bluetooth adapters, FM tuners, etc.http://www.statemaster.com/encyclopedia/SDIO

Collateral Functions

Other functions which can be included in a PDA are:

• Camera, for still shots and video
• Audio recorder
• GPS
• Cell Phone
• Media Player

• Abacus PDA Watch
• Acer N Series
• AlphaSmart
• Amida Simputer
• BlackBerry
• Fujitsu Siemens Loox
• HP iPAQ
• iPod Touch
• iPhone
• Palm, Inc.
• PocketMail
• Psion
• Sharp Wizard and Sharp Zaurus
• Sidekick
• Royal