As the name suggests iPhone 4 belongs to the fourth
Retina Display: The iPhone 4 has a 3.5 inch display with a basic resolution of 960 by 640 pixels making the text extremely sharp and graphics incredibly vibrant. Brilliant color and contrast is IPS technology usage.
Video Calling: The front-facing camera is specially installed for serving video calls enabling video conferencing anywhere and anytime.
Engineered Glass: In iPhone 4, two shiny panels of aluminosilicate glass contains all the advanced technology between them. The Aluminosilicate glass is the same type of glass used in the windshields of helicopters and high-speed trains. And the best thing; it is recyclable.
Stainless Steel Band: iPhone 4 also has a Stainless Steel band which is five times stronger than standard steel providing amazingly thin refined design and extraordinary structural rigidity.
Apple A4 Chip: The A4 chip developed by its engineers can easily perform various complex jobs such as multitasking, editing videos, and placing FaceTime calls.
Gyroscope & Accelerometer: iPhone 4 consists of an integral three-axis gyroscope; which when joined with the accelerometer, makes iPhone 4 competent enough to offer advance motion sensing features for an enhanced gaming experience.
Camera LED & iMovie: The iPhone 4 camera with a backside-illuminated sensor shoots lovely 5-megapixel photos and astonishing HD videos even in low-light settings. The en suite LED flash not only works as a flash during picture capturing but also stay on to light up the scene while shooting a video. Moreover, it is ideal for making FaceTime calls and shooting self-portraits.
Search Engine Bing: Though Google will still be the iPhone's default search engine but Yahoo and Bing-powered searches will also be available as options.
iBooks for iPhone: Apple enables its users to start reading an iBook on an iPhone. They can now download purchased books to all their supported devices without any extra charge.
iAds: iAds is Apple's latest in-application advertising platform. It provides an interactive experience without causing users to leave apps or lose work unlike traditional banner ads that drive out users from applications into Web browsers.
Mic & Speaker: iPhone 4 has two mics contrasting most phones which have only one microphone. The main mic and the second mic offer phone calls, voice commands, memos and FaceTime calls. They also enable dual-mic noise suppression that helps in making each conversation a quiet one.
Advantages of iPhone 4 over iPhone 3GS are as follows :