IPHONE 4S

The iPhone 4S is a touchscreen-based smartphonedeveloped by Apple Inc. It is the fifth generation of theiPhone^[5], succeeding the iPhone 4, and was announced on October 4, 2011. It became available for pre-order on October 7, 2011 in seven initial countries (United States, Canada, Australia, United Kingdom, France, Germany and Japan) with the first delivery date set for October 14, 2011, and available on that same day for direct in-store sales in those countries. It was released in 22 more countries, including Ireland, Mexico, and Singapore, on October 28.^[6]

The phone retains the exterior design of its predecessor, but hosts improved hardware specifications and softwareupdates.^[7

There were no external differences between the iPhone 4CDMA model and the iPhone 4S, with the exception of a SIM card slot on the iPhone 4S.

IPHONE 4S uses IOS mobile operatin system.the 4s uses the IOS 5.1.1 which was released on May 7, 2012. It can act as a hotspot, sharing its internet connection over WiFi, Bluetooth, or USB,^[35]

^The iphone 4s introduced a new automated voice control system called ‘Siri’.The siri allows the user to give commands ,which it can execute and respond to.

The iPhone 4S uses the Apple A5 system-on-a-chip  that incorporates an Imagination Technologies PowerVR SGX543 graphics processing unit.

On April 24, 2012, AT&T announced that 7.6 million iPhone units were activated in Q4 2011, and 4.3 million in Q1 2012. In total, AT&T sold 5.5 million smartphones in the first quarter of 2012, out of which 78% were iPhones