A history of the iPhone

The iPhone debuts

Inspired by a multi-touch display Steve Jobs encountered in the early 2000s, the first iPhone made competition like the BlackBerry (BBRY) look downright antediluvian with a striking industrial design that paired mostly aluminum and scratch-resistant glass. But perhaps more innovative was use of touch: no more trackballs or styluses. Instead, users swiped, pinched, and scrolled with their fingers, making for a more immersive experience. Such innovation cost Apple (AAPL) $150 million in initial development costs, according to one insider, a paltry figure given the company has sold well north of 250 million units since.

The first-generation iPhone

The first-generation iPhone, which initially sold for as much as $599, weighed 4.8 oz. with features considered cutting-edge for the time: a 400-MHz processor, 128 MB of memory, 2-megapixel camera, 3.5-inch display with 320 by 480 resolution, and up to 16 gigabytes of built-in storage. It also ran on AT&T's EDGE networks instead of the faster 3G standard. "Despite some flaws and feature omissions, the iPhone is, on balance, a beautiful and breakthrough handheld computer," Wall Street Journal columnist Walt Mossberg wrote then.

iPhone 3G

How should Apple follow up the 3G-less first-gen iPhone? Why, with the iPhone 3G, of course. The following July, Apple released a 3G-compatible successor that kept many of the same key features but swapped out the aluminum chassis for an optional black or white plastic rear. The company also upgraded iOS to version 2.0 and introduced the App Store, a software platform that now offers 900,000-plus apps.

iPhone 3GS

The iPhone 3GS featured improvements all across the board: a faster processor running at 600 MHz, double the RAM, better 3G performance and battery life, and a 3.2-megapixel rear camera. These upgrades translated to performance Apple claimed was twice as fast as older models. The 3GS sold 1 million units over the first weekend alone.

iPhone 4 'Antennagate'

"Out with the old, and in with the new" seemed the iPhone 4's design motto, ditching previous models' plastic entirely for a glass front and back, surrounded by a stainless steel frame. The frame also served as the 4's antenna, a design decision that raised controversy when users complained that signal strength weakened when they held the phone's lower-left edge. "Antennagate," as it was eventually called, became such an issue Apple released a software update correcting the signal strength indicator and even offered all iPhone 4 users free bumpers, a case that covered the phone's antenna and resolved the issue.

iPhone 4 features

Antenna aside, the iPhone 4 introduced a number of impressive enhancements. Among them: a sharp new screen dubbed the Retina display, which more than doubled the pixel resolution to 960 by 640, a faster 800 MHz A4 chip, a 5-megapixel camera, and double the RAM. "If what you care about, however, is size and shape, beauty and battery life, polish and pleasure, then the iPhone 4 is calling your name," opined New York Times columnist David Pogue then.

iPhone 4S

Apple cemented a new tradition in 2011: When the letter "S" trails the name of a new iPhone, it will look a lot like last year's model. Such was the case with the iPhone 4S, which looked like the 4 on the outside. But on the inside, it included a dual-core A5 processor, 8-megapixel camera and 1080p (a.k.a. HD) video recording capability. The voice-recognition assistant Siri also made its debut, entertaining users with the occasional witty repartee. When proposed to mere hours after setting up the phone, it would say it hardly knew you. Push the subject, and it'll claim that her "End User Licensing Agreement does not cover marriage." Like we said, sassy.

iPhone 5

Instead of early summer, Apple opted for a September announcement and roll-out of the iPhone 5, which expanded the screen to 4 inches and used both aluminum and glass on the back, resulting in a sliver of a device that was 18% thinner and 20% lighter than the year before. A new custom-made A6 processor, 1 GB of RAM, an improved 1.3 megapixel front-facing camera, and a tweaked 8-megapixel shooter rounded out the hardware side, resulting in real-world performance up to twice as fast.

iOS 6

The iPhone 5 came loaded with iOS 6, perhaps most notable in hindsight for the introduction of an all-new Apple Maps. While many users reported a hassle-free experience, many others complained of incorrect directions or inaccurate maps with missing landmarks. The Maps controversy became so bad, Tim Cook apologized in a letter to customers. "We are extremely sorry for the frustration this has caused our customers, and we are doing everything we can to make Maps better," he wrote. Apple has reportedly been working hard since to improve the app, frequently updating map information and hiring to beef up efforts.

iPhone 5C and iPhone 5S

This year marked the introduction of not one, but two distinct, flavors of iPhone: the high-end 5s and long-rumored, budget-minded 5c. The former keeps the industrial design of last year's model but also comes in champagne gold. It also sports a 64-bit A7 processor, which doubles performance, and a fingerprint scanner called Touch ID. Available in five different colors, the "unapologetically plastic" 5c starts at $99, or $100 less than its sibling. Despite speculation that sales might not match previous years, Apple surprised yet again, selling 9 million 5s and 5c devices during their first three days on sale -- a new record, Cook pointed out.