The iPhone 4 was released this week as well as a new version of Apple’s iPhone OS (now called iOS). I’ll have my review of the phone next week, but this week I want to focus on what’s new and different in iOS 4.

The major feature of iOS 4 is multitasking. Before iOS 4, any time you hit the home button the running application would shut down, losing your place in the app or stopping your streaming music. Rather than shutting down entirely, iOS 4 carbon freezes applications Han Solo-style. If you double-tap on the home button, you’ll see a list of running applications. Tap on the icon and the application will thaw out and be ready to use.

The handset offers great connectivity through Bluetooth 2.1 with enhanced data rate along with the 30-pin dock connection for charing and syncing to a compatible PC or Mac.. It also has a 3..5mm jack connection for headphones alongside the integrated microphone and speaker. On the left side within the new stainless steel band surrounding the revised overall design of the handset, there are still two dedicated volume keys and a silent key to silence ringing. The power and sleep or wake button is still situated on top, as is the Home button at the bottom centre of the front. To the top left corner on the front is a dedicated camera for video calls through a new FaceTime app.

The retina display enhances the 3.5 inch multi-touch screen with the highest pixel resolution and density of any mobile phone so far, with a 326 pixels per inch resolution, everything including all the third-party apps available for download by the user can be brought to a unique clarity and colours. The screen also includes two layers of extra strong and durable glass which is scratch resistant too.