At the Macworld convention 2007 held in San Francisco, Apple launched its first iPhone to claim that this phone would revolutionize the mobile phone industry. The debut phone had come without the plastic keyboard that was prominent in mobiles at that time. A daring move indeed!
Steve Jobs, in his keynote address, called it a revolutionary phone.

The next phone was the iPhone 3G. Where was the iPhone 2? It seems that Apple wanted to highlight 3G technology in the new iPhone.
At Apple’s Worldwide Developers Conference in June. 9 2008, Steve Jobs, again in his black turtleneck, introduced the new iPhone 3G.
This time Apple came with the tagline of “Twice as Fast at Half the Price.”  They keep the price bar low and accelerate the internet speed with 3G. The phone had built-in GPS for expanded location-based mobile services, and it also had iPhone 2.0 iOS software, which adds support for Microsoft Exchange ActiveSync. The iPhone 3G came up with a chipset SFL8900 and a TFT display of 320 x 480 pixels

After the iPhone 3G, Apple launched the iPhone 3GS, which was 2x faster than its predecessor. 
On June 8, 2009, again at the Worldwide Developers Conference, Apple unveiled its third entry in the iPhone lineup.
Phil Schiller, the then Senior Vice President of Worldwide Product Marketing, announced the new iPhone 3GS.
The new features were added to it including, longer battery life, 3 MP autofocus camera, and hands-free voice control.  Apple also included the iPhone iOS 3.0, which enabled 100 more features in iPhone 3GS. These features include cut, copy, MMS, landscape keyboard, and spotlight search. After iPhone 3GS, users had access to Apple’s App Store to download useful apps. The phone used the processor of chipset APL0298C05, with a TFT display of 320 x 480 pixels TFT, OS iOS 3.

On 7th June 2010, Apple launched its fourth phone, iPhone 4. The then latest phone featured FaceTime and Retina display that enabled video call and high-resolution display. The iPhone also had a 5 MP camera outnumbering its predecessors, and for the first time, the iPhone brought a front camera with 0.3 Mega Pixels. Interestingly, the iPhone also brought a glass and stainless steel thinnest body, making it the thinnest mobile at that time. iPhone 4 incorporated the newest version of the phone operating system, iOS 4 that included 1500 new APIs for the developers.

The first phone after the stepping down of Steve Jobs was iPhone 4S. It was launched on 4th October 2011. The iPhone 4 featured Apple’s dual-core A5 chip for trailblazing fast performance, 1080p full HD video recording, and the virtual assistant Siri. iPhone 4 came with iOS 5 that included 200 new features, including the remarkable cloud service, i.e., iCloud. The 16GB model’s price was decided as $199, the 32GB model at $299, and 64 GB at $399.

This time Apple worked on revamping its iPhone’s design and brought iPhone 5 with the 4-inch diagonal screen having 326 pixels per inch on 12th September 2012. iPhone 5 came with an A6 chip and iOS 6. iPhone 5 was the thinnest smartphone with a 7.6mm anodized aluminum body.  It supported ultrafast wireless standards, including LTE and DS-HSDPA, which enabled faster browsing in iPhone 5. The camera was upgraded to 8 megapixels covered with a sapphire crystal lens

It was the first time Apple launched two iPhones that have the same sizes in the same calendar year. The iPhone 5s was simply the successor of the iPhone 5, and the intent behind unleashing the iPhone 5c was to provide users an affordable, world-class phone. The announcement was made on September 16, 2013. The iPhone 5s includes the Apple’s A7 64-bits chip, True Tone Flash in 8-megapixels camera, and the feature like Touch ID fingerprint scanner integrated into its Home button allows the user to unlock their phone through a simple touch.

iPhone 5C had an A6 chip and a 4-inches Retina display.
iPhone 5S and iPhone 5C both developed on iOS 7,  which had plenty of new features. The user interface was changed, the color palettes were updated. iOS 7 also introduced iTunes Radio, a free Internet radio service. iPhone 5S had a $199 for a 32 GB model, and the iPhone 5C was priced at $99 for 16 GB.

In the next year of 2014, Apple again unveiled two iPhones, but this time the phones had different sizes. iPhones had 4.7-inches, and iPhone 6 Plus had a 5.5-inches screen. These phones were using the Apple-designed second-generation 4 bits A8 chip. In following the tradition, Apple also made updates in its phone iOS and introduced the Health app, Family Sharing, and iCloud Drive in iOS 8.

iPhone 6 and iPhone 6 Plus introduce Apple Pay, an easy way to securely pay for physical goods and services in stores or apps with just the touch of a finger. iPhone 6 was priced at $199 for the 16GB model, $299 for the 64GB model, and for the first time, a new 128GB model for $399. The iPhone 6 Plus was made available in the US for a retail price of $299 for the 16GB model, $399 for the 64GB model, and $499 for the new 128GB model.

On September 9, 2015, Apple revealed iPhone 6S and iPhone 6S Plus. The phones have a multi-touch sensor that detects the touch of different forces and executes the process. iPhone 6s and iPhone 6s Plus also had a transformative new camera approach, i.e., Live Photos.

iPhone 6 and iPhone 6 Plus introduce Apple Pay, an easy way to securely pay for physical goods and services in stores or apps with just the touch of a finger. iPhone 6 was priced at $199 for the 16GB model, $299 for the 64GB model, and for the first time, a new 128GB model for $399. The iPhone 6 Plus was made available in the US for a retail price of $299 for the 16GB model, $399 for the 64GB model, and $499 for the new 128GB model.

The iPhone 7 and iPhone 7 plus was built on the new custom-designed Apple A10 Fusion chip. It runs up to two times faster than iPhone 6. iPhone 7 and iPhone 7 Plus came with the new iOS 10. iOS 10 brought a huge update to messages that ensured animated ways to message your contacts. iPhone 7 Plus also gets a dual camera and optical zoom.
The 12-megapixel camera was also equipped with optical image stabilization on both phones. A larger ƒ/1.8 aperture and 6-element lens enable brighter and more detailed photos and videos.