PDA - Personal digital assistant

A personal digital assistant (PDA) is a handheld computer, also known as a palmtop computer. Newer PDAs also have both color screens and audio capabilities, enabling them to be used as mobile phones, (smartphones), web browsers, or portable media players. Many PDAs can access the Internet, intranets or extranets via Wi-Fi, or Wireless Wide-Area Networks (WWANs). Many PDAs employ touch screen technology.

The first PDA is considered to be the CASIO PF-3000 released in May 1983. GO Corp. was also pioneering in the field. The term was first used on January 7, 1992 by Apple Computer CEO John Sculley at the Consumer Electronics Show in Las Vegas, Nevada, referring to the Apple Newton. In 1996 Nokia introduced the first mobile phone with full PDA functionality, the 9000 Communicator, which has since grown to become the world's best-selling PDA and which spawned a category of phones called the smartphone. Today the vast majority of all PDAs are smartphones, selling over 150 million units while non-phone ("stand-alone") PDAs sell only about 3 million units per year. The RIM Blackberry, the Apple iPhone and the Nokia N-Series are typical smartphones.

Source PDA (Personal digital assistant):
wikipedia.