That said, the iPhone 4 was a major step forward over its predecessors in a number of areas. First, the iPhone 4 was visibly different from earlier versions thanks to its more-square shape (gone were the iPhone 3GS’ tapered sides), a microSIM slot on its side, and circular volume buttons on the left. When looking at the iPhone 4 it was also immediately clear that something had changed: the screen was much higher resolution. It was the first iPhone to use the Retina Display screen technology. Thanks to its introduction of now-standard iPhone features—such as FaceTime, Retina Display, two cameras, and onboard video editing—the iPhone 4 is the first modern iPhone, the precursor to the iPhone 5S and 5C, and the first iPhone to break with the lineage of the original model.

iPhone 4 Features

In addition to the standard features of an iPhone (cellular data connection and Wi-Fi networking, multitouch screen, App Store support, GPS, Bluetooth, etc.), the iPhone 4 sported:

Apple A4 processor (the same chip used in the original iPad). 3.5-inch, 960 x 640 Retina Display screen, with greater pixel density (326 pixels/inch), leading to higher-quality images. 2 cameras: front- and back-facing, with LED camera flash for back camera5 megapixel camera on the back 720p (high-def) video recording at 30 frames/second, with LED flash; the new iMovie app for iPhone provides on-camera video editing VGA quality images from user-facing camera FaceTime video calls (only worked on Wi-Fi and for iPhone 4-to-iPhone 4 calls when introduced. That later changed as more models and OS updates were released). The iPhone 4 was the first Apple device to support FaceTime. 512 MB of RAM. Gyroscope (combined with accelerometer to offer 6-axes for better gaming) added to the standard set of iPhone sensors. Existing apps took advantage of new screen resolution, but looked best after updating by developers. Twenty-four percent thinner than iPhone 3GS. New body design featured glass front and back, and steel sides. The seam near the bottom of the phone accommodated a larger antenna, which Apple said would result in fewer dropped calls.

Antennagate Controversy

The iPhone 4 was the first iPhone to have its cellular antenna exposed on the outside of the phone’s body (the small lines at the top and bottom edges of the phone are the antennae). Originally hailed as a design breakthrough, people soon reported that holding the iPhone by the bottom would cause a drop in cellular signal strength and sometimes even dropped calls. Apple’s initial reluctance to acknowledge this problem (the situation is common to many smartphones, not just iPhones) led to the affair being dubbed “Antennagate.”

iPhone 4 Hardware Specs

Screen 3.5 inch960 x 640 pixels, 326 pixels per inch CamerasFront Camera:

VGA photos

Back Camera: 

5 megapixel photos720p HD videoat 30 frames/second

iOS Version SupportCame pre-loaded with iOS 4Supports:

iOS 5 iOS 6 iOS 7 (with some limitations and cautions)

iPhone 4 Capacity16 GB32 GB iPhone 4 Battery Life all times in hours iPhone 4 Size and WeightWeight in ounces; dimensions in inches