The Apple iOS 4.2 and iOS 4.3 Beta are different in many aspects. Many new features are coming with iOS 4.3, but it is still at the development centre. The last Apple iOS for iPad touch and iPhone was 4.2.1, which was released in November 2010. Apple iOS 4.2 (Apple iOS 4.2 full features) offered many good features and functions like Multitasking, background audio, voice over IP, location notifications, Airplay, Airprint, Ad, Find my phone, game center, directory enhancement, messages with tone and supports 50 languages. The OS for Verizon iPhone 4, which is a CDMA iphone, was released with 4.2.5.
Apple iOS 4.3 beta
Apple iOS 4.3 beta introduces the following new features
(1) Third party apps can use Airplay functionality from OS which was basically supported by Safari and Youtube App.
(2) Apple iOS 4.3 beta introduces multitouch gestures to get support more interactions.
(3) In Apple 4.3 there is an added option for returning the hardware orientation.
(4) Apple iOS 4.3 introduced full screen advertisement banners.
Apple iOS 4.3 beta version is in the Apple Development Center