The iPhone 4 uses the same custom A4 processor as the iPad, and gets a new "Retina Display" which has four times the pixel density of existing iPhones. This makes the iPhone display much sharper than before, with Apple describing it as being of similar quality to a printed page.

The iPhone 4's main camera has 5MP, and is capable of recording full 720p HD video. The iPhone also gets a front-facing camera which can be used for video calling using the new Facetime feature.

Due to an expanded battery and the A4 processor's enhanced power management, battery life is significantly extended.

The iPhone 4 will ship with the new operating system, now to be known as iOS4. This operating system allows full multi-tasking as well as many other new features, including support for the iBooks application and online bookstore.

iOS4 will be available as a free upgrade for earlier model iPhones and iPod Touch devices, though these will not be able to support all features.