• Apple's first iPhone debuted in 2007 with the trademark home button, a metal rear casing, and just a 3.5-inch display. Its capacitive touchscreen laid the foundations for modern smartphones.
• Apple's second iPhone was a big departure from the original. The iPhone 3G dropped in price thanks to a new plastic rear, but also gained 3G connectivity, GPS, third-party apps, and a white model to choose from. A rounded rear completed the look, and button placements remained the same.
• Apple's third iPhone is practically identical to its second. The iPhone 3GS has the same plastic rear, but Apple made the iPhone text stand out with a silver color. Inside, Apple focused on speed improvements and a 3-megapixel camera capable of recording video. Apple also introduced a voice control feature alongside a highly requested cut, copy, and paste feature in iOS 3.
• Apple’s first major redesign of the iPhone featured a combination of stainless steel and glass. Both the front and back of the iPhone 4 is covered in glass, and the square and flat look is a radical departure from the previous 3GS model. Apple also introduced a forward-facing camera with FaceTime, a 3.5-inch Retina display, and a 5-megapixel camera with LED flash.
• Just like the 3G to 3GS upgrade, Apple’s iPhone 4S looks identical to the iPhone 4. After the infamous antennagate episode with the iPhone 4, the 4S improved on the dual-antenna design capsulated in the stainless steel band, all while gaining a faster processor, an 8-megapixel camera with 1080p video recording, and support for the Siri digital assistant.
• Apple’s second major redesign of the iPhone arrived with the iPhone 5. An all-new aluminum design encased a larger 4-inch display into the thinnest and lightest iPhone so far. Surprisingly light to hold, the iPhone 5 also included an improved 8-megapixel camera with a sapphire crystal lens cover and HD FaceTime camera at the front. Alongside the radical design, Apple switched to a new Lightning connector and redesigned its EarPod headphones.
• While many were expecting the iPhone 5C to be a budget iPhone, it debuted as an iPhone 5 with a plastic rear. That made it slightly cheaper, but its internal components are identical to the iPhone 5. While Apple had always stuck to black and white color combinations for its iPhone, the iPhone 5C introduced some much needed color to the range.
• Continuing the S trend, Apple’s iPhone 5S is almost identical in appearance to the iPhone 5 at first glance. New color combinations differentiate it from the 5, and a gold option offered an alternative to the typical black or white. Apple also redesigned its home button for the first time with the iPhone 5S, adding a fingerprint Touch ID sensor to unlock the device by simply touching your finger on the home button.
• Apple's latest iPhones have one unmistakeable feature: size. The iPhone 6 is has a 4.7-inch display, and the iPhone 6 Plus jumps to 5.5 inches. Both have Retina HD displays with a curved body and NFC chips for Apple Pay, but the iPhone 6 Plus includes optical image stabilization with its 8-megapixel camera.