The IBM Simon Personal Communicator is a handheld, touchscreen PDA designed by International Business Machines (IBM), and manufactured by Mitsubishi Electric. Although the term "smartphone" was not coined until 1995, because of Simon's features and capabilities, it has been retrospectively referred to as the first true smartphone.

A personal digital assistant (PDA) is a multi-purpose mobile device which functions as a personal information manager. PDAs have been mostly displaced by the widespread adoption of highly capable smartphones, in particular those based on iOS and Android, and thus saw a rapid decline in use after 2007.