Short for personal digital assistant, PDA is a computer that fits in the palm of your hand to help collect such information as contacts, appointments, files, and programs. The picture is the Palm Tungsten | E2 and an example of a PDA. Because touch screens were not available at the time to use a PDA a stylus was used to input data into the device. As the PDA couldn't connect to the Internet, to backup or transfer data, it had to connect to a computer by a serial port.
The term PDA was first used by John Scully at CES (Consumer Electronics Show) on January 7, 1992, while describing the Apple Newton. Today, with the popularity and advances in smartphones, PDA's are rarely found and used as users migrate to smartphones like the iPhone.