IPhone its older iPhones when issuing operating system upgrades. It has spurred allegations that the firm has been using this as a tactic to prompt users of older iPhones to buy newer models. Up to the iPhone 4, all iPhone models, as well as other iOS devices were manufactured exclusively by Foxconn, based in Taiwan. In 2011, after Tim Cook became CEO of the company, Apple changed its outsourcing strategy, for the first time increasing its supply partners. The iPhone 4s in 2012 was the first model which was manufactured simultaneously by two stand-alone companies: Foxconn as well as Pegatron, also
IPhone placement of the microphone and speaker on the base on the unit—the speaker is on the right. Volume controls are located on the left side of all iPhone models and as a slider in the iPod application. The 3.5mm TRRS connector for the headphones is located on the top left corner of the device for the first five generations (original through 4S), after which time it was moved to the bottom left corner. The headphone socket on the first-generation iPhone is recessed into the casing, making it incompatible with most headsets without the use of an adapter. Subsequent generations eliminated