Personal digital assistants (usually abbreviated to PDAs) are handheld devices that were originally designed as personal organizers, but became much more versatile over the years. The many uses and tasks of a basic PDA include many features: calculating, use as a clock and calendar, playing computer games, accessing the Internet, sending and receiving E-mails, use as a radio or stereo, video recording, recording notes, use as an address book, and use as a spreadsheet. Newer PDAs also have both color screens and audio capabilities, enabling them to be used as mobile phones (PDA Phone), web browsers or media players. Many PDAs can access the Internet, intranets or extranets via Wi-Fi, or Wireless Wide-Area Networks (WWANs).
Like a personal computer, it is possible to install additional software on most PDAs. Software can be bought or downloaded from the Internet, allowing users to personalize their PDAs to their liking. Some PDAs also allow for adding hardware. The most common is a memory card slot, which allows the users to get additional and exchangeable storage space on their handheld devices. There are also miniature keyboards that can be connected to some PDAs for quicker text input. PDAs with Bluetooth can also use Bluetooth devices like headsets, mouse and foldable keyboards with their PDAs.
Other functions are commonly added to PDAs. Some examples are:
* Audio recording.
* Camera functionality, allowing users to take photos or short video clips.
* Map functionality, with a GPS receiver for localization.
* Cell Phone functionality, which lets users make and receive phone calls, SMS and MMS messages.
* Media Player abilities.
The most common memory cards used.
mini-SD Cards
MMCMobile/DV-RS-MMC Cards
TransFlash/Micro-SD Cards
Memory Stick Pro Duo Cards
Compact Flash Memory Type 1 & 2