KT Corporation, formerly Korea Telecom, is a South Korean telecommunications company. KT is the second-largest wireless carrier in South Korea, with 16.493 million subscribers as of Q4 2017.

The iPhone 4 is a smartphone that was designed, developed, and marketed by Apple Inc. It is the fourth generation of the iPhone lineup, succeeding the iPhone 3GS and preceding the 4S. Following a number of notable leaks, the iPhone 4 was first unveiled on June 7, 2010, at Apple's Worldwide Developers Conference in San Francisco, and was released on June 24, 2010, in the United States, United Kingdom, France, Germany, and Japan. The iPhone 4 introduced a new hardware design to the iPhone family, which Apple's CEO Steve Jobs touted as the thinnest smartphone in the world at the time; it consisted of a stainless steel frame which doubled as an antenna, with internal components situated between two panels of aluminosilicate glass. The iPhone 4 introduced Apple's new high-resolution "Retina Display", while maintaining the same physical size and aspect ratio as its precursors, Apple's A4 system-on-chip, along with iOS 4—which notably introduced multitasking functionality and app folders. It was the first iPhone at the time to include a front-facing camera, which made possible Apple's new FaceTime video chat service, and the first to be released in a version for CDMA networks, ending AT&T's period as the exclusive carrier of iPhone products in the United States.