First announced at the January 2007 Macworld in San Francisco, and released the following June, the iPhone marked Apple's major move into the smartphone market.
In the U.S. market, the original version of the iPhone was exclusive to AT&T, and ran on AT&T's EDGE cellular network. Available in 4 and 8 GB models, the iPhone had a touch-based interface with a single button that took users back to the home screen.
The iPhone incorporated Apple's iPod music player and provided the ability to view movies, TV shows, and videos, capture and display photos, and run applications.
In its original incarnation, the iPhone only supported web-based applications, but within a short time developers were writing native code applications. Apple embraced iPhone developers soon after, providing iPhone SDKs (Software Developer Kits) and development tools.
The iPhone was a runaway success. Follow-on models addressed the shortcomings of the original version, upgrading speed, adding more memory, and creating an application base that rivals anything available for other smartphones.