A smartphone is large-screen, data-centric, handheld cellular device designed to offer complete phone functions whilst simultaneously functioning as a personal digital assistant (PDA).
IBM developed the first cellular smartphone known as “Simon” which was marketed by BellSouth. It used a touch-screen to select phone numbers with a finger or create facsimiles and memos with an optional stylus. Text was entered with a unique on-screen "predictive" keyboard. By today's standards, the Simon would be a fairly low-end smartphone. Since then, smartphones have evolved into what amounts to very small computers, offering almost the same kind of flexibility and services that a regular PC offers.
In 1996, Nokia and Hewlett Packard collaborated to develop the first true smart phone – named the Nokia communicator series starting with Nokia 9000. The next in the series - Nokia 9210 was the first color screen Communicator model which was the first true smartphone with an open operating system, while still being referred as commuicator. The latest E90 Communicator includes GPS. The Nokia Communicator model is remarkable also having been the most expensive phone model sold by a major brand for almost the full lifespan of the model series.
In addition to functioning as a cellular telephone, a smartphone's features may include: