Apple just announced that it has reached a major and impressive milestone, as it has sold its 1 billionth iPhone. The handset wasn't the first smartphone but it was the first that introduced intuitive features like multi-touch and sensors and has had major influence in every device that has come since.

In 2004 Apple was riding the enormous success of the iPod, its mp3 player that turned the music industry on its head. The company introduced the iPod mini in January of that year and also began secretly working on a new device that would turn the technology world upside down, become a pop culture phenomenon, reinvent the phone, and make Apple the most successful company in history.

Apple's secret and confidential project was called "Project Purple" and Steve Jobs had a team of 1,000 employees working on the device. Initially, the new gadget was more iPad-like, since its original focus was that of a tablet. Steve Jobs' vision of the device began to change and he wanted to do to cellphones instead.

Apple officially announced the first iPhone on Jan. 9, 2007 and began selling the smartphone on June 29, 2007. There wasn't an App Store and it only ran applications created by Apple.

The App Store made its debut in iOS 2, which was released as an upgrade to iPhone and iPod touch owners and preinstalled on the iPhone 3G, also released in July 2008.

The first "S" moniker iPhone hit store shelves in 2009, when the iPhone 3GS was released and shared the same design as that of its predecessor.

The iPhone 4 garnered huge attention before it was ever even announced by Apple, when it was discovered in the wild when an Apple employee accidentally forgot it in a bar. Soon after its release in 2010, Apple faced backlash when it was discovered that the new metal and glass design had a flaw, as the antennas were built into its outer metal ring and users were reporting lower reception when holding the handset.

Apple unveiled the iPhone 4S at an event on Oct. 4, 2011 and introduced the world to Siri, a digital personal assistant living inside the handset. The iPhone 4S was the first iPhone launch Steve Jobs didn't appear at and it was later revealed Jobs watched the event from his home and passed away the following day, Oct. 5, 2011.

The iPhone 5 was the first iPhone to ship with a larger display. While Steve Jobs claimed the 3.5-inch display found on the original through iPhone 4S was the perfect size, Tim Cook as CEO introduced the smartphone in 2012.

Touch ID and powerful 64-bit A7 processor were the two biggest features included with Apple's iPhone 5S, released in 2013. The company also introduced a less expensive iPhone 5C alongside the iPhone 5S.

In response to the legions of Android smartphones using larger displays, Apple once again increased the size of the screens of its flagship smartphones when it released the 4.7-inch iPhone 6 and 5.5-inch iPhone 6 Plus in 2014.

iPhone 6S and iPhone 6S Plus would bring the same design of the iPhone 6 series but its defining feature was 3D Touch, which Apple billed as the biggest interface innovation since multi-touch. 3D Touch has become even more advanced and feature-rich in iOS 10, which is available in beta form and will be released alongside the upcoming iPhone 7 and iPhone 7 Plus/Pro.

In March 2016, Apple introduced the iPhone SE, which uses a similar 4-inch display and design to that of the iPhone 5S but includes similar specs found in the iPhone 6S and 6S Plus.

All of these iPhones have had a huge impact on our everyday lives and whether you use an Android, Windows Phone, BlackBerry, Tizen, or something else, there's no denying Apple and its iPhone have influenced those devices. So it's no wonder that Apple has just sold its one billionth iPhone.

"iPhone has become one of the most important, world-changing and successful products in history. It's become more than a constant companion. iPhone is truly an essential part of our daily life and enables much of what we do throughout the day," said Cook. "Last week we passed another major milestone when we sold the billionth iPhone. We never set out to make the most, but we've always set out to make the best products that make a difference. Thank you to everyone at Apple for helping change the world every day."