How the iPhone Works

iPhone 4

When Steve Jobs unveiled the iPhone 4 in 2010, he confirmed a lot of rumors that had been swirling around for more than a month. The technology news blog Gizmodo made headlines of its own when it ran a story about a prototype version of the iPhone 4 ahead of the official announcement. The phone belonged to an Apple employee who apparently left it behind at a bar by accident. Gizmodo revealed many of the phone's features, though Apple had remotely locked most of its functionality.

Jobs slyly acknowledged the fact that his audience knew more about the phone than they should, but he still had some surprises up his sleeve. The new iPhone's design was a departure from previous models. Instead of the slightly curved back, the iPhone 4 has flat surfaces. It also has two cameras. The rear-facing camera takes 5-megapixel pictures and can capture 720p video. It also has an LED flash for low-light photography [source: Apple]. The front-facing camera plays a part in Apple's Facetime app, which lets you make video calls to other iPhone 4, compatible iPod touch and Mac OS X users.


The phone's front and back are both covered in glass. Metal bands around the edge of the phone act as antennae.

The iPhone 4 has what Apple calls a retina display. Its resolution is 960 by 640 pixels, or 326 pixels per inch. It has an 800-to-one contrast ratio.

Other iPhone 4 features include:

  • Multitasking
  • HD video recording and editing
  • camera autofocus
  • three-axis gyroscope
  • dual-mic noise suppression

A year after the release of the iPhone 4, Apple used its annual WWDC event to announce something new -- but it wasn't a new phone. It was the next iteration of its mobile operating system, iOS, with some major improvements in tow.