History of iPhone
On January 9, 2007, Steve Jobs announced iPhone at the Macworld convention, receiving substantial media attention. Jobs announced that the first iPhone would be released later that year. On June 29, 2007, the first iPhone was released.
IPhone 4S
This iPhone was named "4S" where "S" stood for Siri an iPhone 4S-exclusive intelligent personal assistant that was later included in future generations of mobile Apple products. Retaining most of the external design of the iPhone 4, the 4S hosted major internal upgrades, including an upgrade to the Apple A5 chipset, and an 8-megapixel camera with 1080p video recording. It debuted with iOS 5, the fifth major version of iOS, Apple's mobile operating system, that introduced features including iCloud, iMessage, Notification Center, Reminders, and Twitter integration.