Processing power
It was always a forgone conclusion that the 1GHz single core A4 processor used in the iPhone 4 would be superseded by an iPhone equipped with the dual-core A5 processor as seen in the iPad 2. The benefits of the A5 are clear it allows the use of apps that are off-limits to the original iOS devices, such as Garageband and Siri. What's not clear is if the iPhone 4S A5 is clocked at 1GHz just like the iPad 2.
Cameras
We have to admit that we were hardened sceptics about the utility of camera phones when they first appeared on the market seven years ago. Now, we're the most prolific smartphone camera users the most useful camera is the one you have on you. Especially if you can share photos simply by uploading to Flickr and Facebook, or shoot and edit HD footage then and there. The iPhone 4's five megapixel camera doesn't have dual-flashes or shoot in 3D, but it produces some of the most balanced looking images around.
The iPhone 4S has an eight megapixel rear-facing camera that can also shoot 1080p HD video as opposed to the 720p video recording found on the iPhone 4. The improvements aren't just about higher specs though. As well as features such as image stabilisation, noise reduction, face detection and better white balance, Apple claims the iPhone 4S camera is better at producing good looking pictures in dimly lit conditions than its predecessor. Apple claims the iPhone 4S camera is faster at taking a new photo from sleep and taking multiple shots one after the other - 1.1 and 0.5 seconds respectively which is around half as long as the HTC Sensation according to Apple.
